Fm:QV'f~CY ANALYSIS QF RIVERFLOW IN .ANll ' -' "' SA.R1WAK

by

A WANG AZFAR B AWANG ALI BAHAR

Submitted to the Civil Engineering Programme in Partial Fulfillment of the Requirements for the Degree BACHELOR OF ENGINEERING (Hons) (CIVIL ENGINEERING)

Universiti Teknologi PETRONAS Bandar Seri Iskandar 31750 Tronoh Oarul Ridzuan

© Copyright 2007 by A wang Azfar bin A wang Ali Bahar, 2007 CERTIFICATION OF APPROVAL

FREQUENCY ANALYSIS OF RIVERFLOW IN SABAH AND

by

A wang Azfar b A wang Ali Bahar

A project dissertation submitted to the Civil Engineering Programme Universiti Teknologi PETRONAS in partial fulfilment of the requirement for the BACHELOR OF ENGINEERING (Hons) (CIVIL ENGINEERING)

Approved by,

(A ssoc sPro for. s a1e·d's ae1·d·) 1

UNIVERSITI TEKNOLOGI PETRONAS TRONOH, PERAK JUN 2007

I CERTIFICATION OF ORIGINALITY

This is to certify that I am responsible for the work submitted in this project, that the original work is my own except as specified in the references and acknowledgements, and that the original work contained herein have not been undertaken or done by unspecified sources or persons.

A WANG AZFAR B A WANG ALI BAHAR

II ABSTRACT

Design flood estimation is an important task that is required planning and design of many civil engineering projects. In this study, the flood records of 37 stations in Sabah and 5 stations in Sarawak are examined using six probability distributions mostly used in Flood Frequency Analysis which are Weibull Plotting Position, Log-Pearson III, Gumbel Type I, Log-Normal 2, Log Normal 3 and Pearson Ill. This is a continuation project of Frequency Analysis in Peninsular made by Miss Nabila Abu Bakar, to complete the study on Frequency Analysis for Malaysia. The primary objective of frequency analysis is to relate the magnitude of occurrence, flood in this case through the use of probability distributions. To ease the process, software called DISTRIB which developed •· by A.P Dr Saied Saiedi (1989) is used to obtain more accurate result. A best fit distribution with the lowest error is subsequently developed for each station. The results presented herein are useful for reference for practicing engineers and will be used to predict high streamflow on any return period.

III ACKNOWLEDGEMENTS

All praise to Allah, Lord of the worlds, who, through His mercy and grace, has revealed some of His knowledge to me in the course of this training. Verily all good are from Allah and all shortcomings are due to my own weaknesses.

The successful implementation and completion of this research has been made possible through the help and support of many individuals:

I. Assoc. Prof. Dr. Saied Saiedi (Project Supervisor) II. Miss Koh Moi Ing (FYP Coordinator) III. Mr. Ho Tsun Lin (Assistant Director, DID Sabah) IV. Mr. Dos Saguman (Technical Assistant, DID, Sabah) V. Mrs.Chin Lee Yun (Technical Assistant, DID, Sabah) VI. Puan Hidayati (DID Engineer) VII. Mr. Chia Kia Pin (Technical Staff, DID Sarawak)

Also to Hydrology Division; Department of Irrigation and Drainage in each divisional area who provides information on geographical characteristic in assisting the project.

Finally I would like to thank Civil Department of University Teknologi PETRONAS and all those who have help me in one way or another to make my Final Year Project a success.

IV TABLE OF CONTENTS CERTIFICATE OF APPROVAL...... I CERTIFICATE OF ORIGINALITY...... II ABSTRACT...... III ACKNOWLEDGEMENTS...... IV LIST OF TABLES...... VIII LIST OF FIGURES...... IX

CHAPTER 1: INTRODUCTION...... 1 1.1 Project Background ...... 1.2 Problem Statement...... 2 1.3 Objectives ...... 3 1.4 Scope of Study...... 3

CHAPTER 2: LITERATURE REVIEW...... 4 2.1 Distribution in Flood Frequency Analysis...... 4 2.2 Publication by Department of Irrigation and Drainage Malaysia...... 5 2.3 Influence of Urbanization to Flood in Malaysia...... 7 2.4 Flood Frequency in Malaysia...... 8

CHAPTER 3: FLOOD FREQUENCY ANALYSIS...... I 0 3.1 Introduction of Frequency Analysis...... 10 3.2 Return Period...... I 0 3.3 Hydrological Frequency Distributions...... II 3.3.1 Weibull Plotting Position...... 12 3.3.2 Log Pearson III...... 13 3.3.3 Gumbel Type!...... 15 3.3.4 Log-Normal2...... 17 3.3.5 Log-Normal III...... 18 3.3.6 Pearson Ill...... 19

v CHAPTER 4: RAINFALL AND IN SABAH AND 20 SARAWAK ...... 4.1 Rainfall...... 20 4.2 Rivers in Sabah and Sarawak...... 24 4.2.1 Sabah...... 24 4.2.2 Sarawak ...... ,...... 26

CHAPTER 5: FLOOD IN SABAH AND SARA WAK...... 28 5.1 Flood Event in Sabah...... 28 5.2 Flood Event in Sarawak ...... 33

CHAPTER 6: METHODOLOGY...... 35 6.1 Type of Data...... 35 6.2 Data Collection...... 35 6.3 Choice of Stations...... 39 6.4 Analysis of Annual Maximum Discharge Data...... 43

CHAPTER 7: RESULTS...... 45 7.1 Description ofResults ...... ,...... 45

CHAPTER 8: DISCUSSION...... 55 8.1 Curve fitting the best distribution...... 55 8.2 Best Distributions...... 63 8.2.1 Whole of Sabah...... 64 8.2.2 ...... 65 8.2.3 ...... 66 8.2.4 ...... 67 8.2.5 West Coast...... 68 8.2.6 Interior...... 69 8.2. 7 Sarawak...... 70

VI CHAPTER 9: CONCLUSION AND RECOMMENDATION...... 73 9.1 Conclusion 73 9.2 Recommendation 74

REFERENCES...... 7 5

APPENDICES...... 77 Appendix A: Correspondence on Data Collection...... 78 Appendix B: Sample of Output from DISTRIB...... 87 Appendix C: Detail of Stations Analysed...... 88

Vll LIST OF TABLES

Table 3-1 Frequency Factors for Use in Log Pearson III Distribution...... 14 Table 3-2 Reduced Mean and Standard Deviation in Gumbel's Extreme Value...... 16

Table 4-1 16 major rovers of Sabah in different district...... 24 Table 4-2 Main Rivers and Basins in Sarawak...... 25 Table 4-3 Rivers in Sabah and Sarawak...... 27

Table 5-1 Flood Related Disaster in Sabah...... 30 Table 5-2 Official flood loss estimates for selected floods in Malaysia.... 32

Table 6-1 Information on Discharge on river station - Sg Padas at Kemabong...... 39 Table 6-2 Number of stations in Sa bah and Sarawak...... 42

Table 7-1 Summary of River stations in Sabah...... 46 Table 7-2 Summary of River stations in Sarawak...... 4 7 Table 7-3 Detailed information on the rivers in Sabah...... 48 Table 7-4 Detailed information on the rivers in Sarawak...... 51 Table 7-5 Summary of result obtained from Flood Frequency Analysis of Yearly flood in Sabah...... 52 Table 7-6 Summary of result obtained from Flood Frequency Analysis of Yearly flood in Sarawak...... 54

Table 8-1 Curve fitting using Logarithmic functions Sabah...... 56 Table 8-2 Curve fitting using Logarithmic functions Sarawak...... 58

Vlll LIST OF FIGURES

Figure 3-1 Graphical Technique of Estimating Parameter a...... 18

Figure 4-1 Average Monthly Rainfall in Sabah...... 22

Figure 4-2 Jsohyetal Map of Sarawak 2003...... 23

Figure 4-3 Map of rivers in Sabah...... 25

Figure 4-4 Main rivers and basins in Sarawak...... 26

Figure 5-1 Flood in , Sabah, 1998...... 28

Figure 5-2 Flood Prone Areas in Sabah...... 29

Figure 5-3 Flood in , Sarawak, 2004...... 33

Figure 6-1 Graph of Time versus Discharge for Sg. Padas at Kemabong..... 37

Figure 6-2 Description of river station provided by DID...... 38

Figure 6-3 River station analysed in Sabah...... 40

Figure 6-4 River station in Sarawak...... 41

Figure 6-5 No of stations with yearly range data...... 43

Figure 8-1 Best Distribution for rivers in Tawau, Sabah ...... 59

Figure 8-2 Best Distribution for rivers in Sandakan, Sabah ...... 59

Figure 8-3 Best Distribution for rivers in Kudat, Sabah...... 60

Figure 8-4 Best Distribution for rivers in Interior (1), Sabah...... 60 } Figure 8-5 Best Distribution for rivers in Interior (2), Sabah...... 61

Figure 8-6 Best Distribution for rivers in West Coast(!), Sabah ...... 61

Figure 8-7 Best Distribution for rivers in West Coast (2), Sabah...... 62

IX Figure 8-8 Best Distribution for rivers in Sarawak (5 stations only)...... 62

Figure 8-9 The first two best-fit distributions for the whole Sabah...... 64

Figure 8-10 The first two best-fit distributions for the ...... 65

Figure 8-11 The first two best-fit distributions for the ...... 66

Figure 8-12 The first two best-fit distributions for the ...... 67

Figure 8-13 The first two best-fit distributions for the West Coast District..... 68

Figure 8-14 The first two best-fit distributions for the Interior District...... 69

Figure 8-15 The first two best-fit distributions for the Sarawak...... 70

Figure 8-16 Total Mean Discharge versus Catchment Area for Whole Sabah and Sarawak...... 71

Figure 8-17 Total Mean Discharge versus',, Catchment Area for Sabah and 2 Sarawak (Area less than 1000 km )...... •••• 72

Figure 8-18 Total Mean Discharge versus Catchment Area for Sabah and Sarawak (More than 1000 km\...... 72

X CHAPTER I INTRODUCTION

1.1 Project Background

Flood is an unusual high stage in a river which overtops the natural or artificial banks in any reach of a river. Floods are produced when the capacity of the river channel is inadequate to carry off the abnormal quantity of water arising from heavily rainfall. Since the flood plain is a desirable location for man and its activities, it is important that floods can be controlled so that the damage does not exceed an acceptable limit. The knowledge of flood prediction is very important in order to reduce damage caused by high flow of water. It will be used to design structures which are prone to floods such as dams and bridges.

This project is based on statistical method to obtain the frequency analysis of flood occurring in a specified period of time. Statistical methods are utilized to organize, present and reduced observed data to a form that facilitates their interpretation and evaluation.

There are many distributions used in Malaysia to obtain the return period of floods of rivers. The distributions are subjected to some amount of error which will reduce the effectiveness of the design. Recently, there has been no study on the best distribution tbat could be used in Malaysia. This project is a continuation of previous project in obtaining the frequency of flood occurring in Malaysia. The previous project area was in Peninsular Malaysia done by Miss Nabilah bt. Abu Bakar, and this project area will be focus in Sabah and Sarawak.

1 1.2 Problem Statement

The accurate estimation of design floods remains one of the major challenges for many engineers and planners who are involved in project design. The purpose of design flood estimation is to make predictions on the magnitude of flood discharges at a particular section of a river of interest corresponding to a risk level that is acceptable to the design structures. With sufficient length of flow observations at a particular site of interest, one can make statistical inference on the flood discharges corresponding to various acceptable risk levels. Moreover, the magnitude of the design flood directly affects the dimensions and the cost of the structure.

While there are general recommendations over the best choice in method for frequency analysis, the designer and engineers should rely on the specific data of the river and the best method to suit the data. Currently, there is little available study and report on flood frequency analysis for Malaysia. Many practicing engineers in Malaysia are adopted to use Gumbel Type I distribution suggested in the Hydrological Procedure No. 4 (HP 4) for flood frequency analysis recommended by Department of Irrigation and Drainage (DID), Malaysia.

However, the accuracy of frequency analysis is dependent on the amount of input data available from the river gauging station. Sometimes the designer has to work on a limited amount of data to obtain the discharge at a specified return period. This will significantly decrease the accuracy ofthe flood prediction.

2 1.3 Objectives

The main objectives of this project are: • River data collection for Sabah and Sarawak • Check streamflow data for discrepancy • Flood frequency analysis for rivers in Sabah and Sarawak • Appraisal of flood frequency of the common distributions as applied to Malaysian rivers

1.4 Scope of Study

In this project the scope of the study is limited to: • Maximum annual (yearly) flood rivers in Sabah and Sarawak • Rivers with more than I 0 annual floods data are included • Six distributions are evaluated, which are: I. Weibull Plotting Position ii. Log-Pearson III

lll. Gumbel Type I iv. Log-Normal2

V. Log-Normal 3

VI. Pearson III

3 CHAPTER2 LITERATURE REVIEW

2.1 Distributions in Flood Frequency Analysis

Flood frequency study is a statistical approach for the prediction of many hydrologic processes including flood flows and rainfall. The standard procedure to determine probabilities of flood flows consists of fitting the observed stream flow record to specific probability distributions. However, this procedure only works for basins that have 'long enough' streamflow records (minimum 10 years) to warrant statistical analysis.

Kite (1988) discussed eight frequency distributions for the flood frequency analysis. They are discrete distributions, normal distribution, two-parameter lognormal distribution, three-parameter log-normal distribution, type I extremal distribution, Pearson type III distribution, log- Pearson type Ill distribution and type Ill exterrnal distribution. For every distribution, the parameters and standard error are determined using method of moments, maximum likelihood method and other approximation methods. He then compared the frequency distributions of annual maximum daily flows of St. Mary's River at Stillwater, Nova Scotia over the period 1915 to 1986, to find the best fitting distribution using the standard error. From the analysis, type I exterrnal (Gumbel Type I) distribution has the lowest standard error as compared to other distributions. However, this result is not applicable to rivers in other parts of the world due to difference in data sample.

4 Subramanya (1984) discussed on several methods for estimating the magnitude of flood peak of rivers, which are the rational method, empirical method, unit hydrograph technique and flood frequency studies. The use of a particular method depends upon the desired objective, the available data and the importance of the projects. For flood frequency analysis which uses statistical method, he studied on three methods of distributions which are plotting position (Weibull formula), Gumbel Type I method and Log-Pearson type III distribution. He uses a direct approach to come out with the estimated flood for various return periods. Weibull formula for plotting position is a simple empirical technique to arrange the given annual extreme series in descending order of magnitude and to assign an order number. There are several other empirical formulae available to calculate the probability of occurrence. Gumbel's extreme value distribution and log Pearson type III method are two commonly used analytical method discussed. Gumbel defined a flood as the largest of the 365 daily flows and the annual series of flood flows constitute a series of largest values of flows. Gumbel Type I method used a special Gumbel probability paper to graph its distribution. A Gumbel distribution will plot a straight line on a Gumbel probability paper. This property can be used for extrapolation, whenever necessary. Log- Pearson type III distribution is widely used in the USA for projects sponsored by the US Government. In this, the variate is first transformed into logarithmic form (base I 0) and the transformed data is then analysed. This distribution takes into account the skewness (degree of the symmetrical of distribution to the left or right) of the distribution.

2.2 Publications by Department oflrrigation and Drainage Malaysia

Since early 1970's, the Department of Irrigation and Drainage (DID) has published a total of26 Hydrological Procedures (HP) and 20 Water Resources Publications (WRP). These HP's and WRP's have been widely used by engineers, hydrologists, field hydrological personnel and other professionals in projects related to hydrology and water resources. Hydrological Procedure No. 4 describes a flood estimation technique (peak discharge) based on regional analysis. Frequency' analysis was carried out on available runoff data of

5 61 stations using Gumbel Extremal Type I theory. To extend the results of the gauged catchments to ungauged areas, regional dimensionless flood frequency curves and regional regression equations relating mean annual flood to the catchment characteristics (area and annual rainfall) were developed. Estimating flood magnitudes for a given return period can be easily done offer knowing the location of the catchment with respect to the defined flood regions and the catchment areas and annual rainfall. This procedure is 2 applicable to catchment areas greater than 20 km • Nonetheless, this flood estimation technique is not used in this project. However, this paper shows that Gumbel Extermal Type I method is widely used in Malaysia and is recommended by DID.

The discharge data are obtained from DID publications, 'Streamflow and River Suspended Sediment Records'. The book is published for data of every 5 years of duration, for all river stations in Malaysia. The available publications for this project are from year 1975 to 1990 (15 years). All river stations are numbered according to its location, and classified within each state. By referring to the latest publication, there are all together I 00 river stations in the whole of Malaysia, of which 83 are located in Peninsular Malaysia and the remaining 17 are at Sabah and Sarawak. For each river, a detailed description of data is provided, including the location, catchment area and elevation, catchment characteristic and water utilization upstream of the river. Water utilization includes the amount of extraction by Public Works Department for water supply and by Department of Irrigation and Drainage for padi cultivation. The summary of discharges (unit m3/s) includes annual and monthly mean, maximum and minimum streamflow data. The annual maximum of river discharge is the absolute maximum water discharge for each year, and is used for this project. Information on the flow- duration analysis for 5 years duration of each river stations is also included in this publication. These sets of data are used for the estimation of flood using the frequency analysis. After year 1975, DID provided river suspended sediment records for all its river stations. However, this information is not relevant to the study of this project.

6 2.3 Influence of Urbanization to Floods in Malaysia

Highland forests, often referred to as 'water sponges', are able to absorb a significant amount of water from rainfall. It will then causes variation to the rate of flow and volume of water into a river. Wetlands are able to take up excess water from a river system and acts as natural flood control mechanism. Sedimentation of rivers is largely attributed to deforestation in the highlands and large- scale land clearing for urban and agricultural development along the course of a river.

According to Krishnan et a!. (200 I), it is evident that the rapid economic development in Malaysia in recent decades has also been associated with adverse effects upon the environment. One of the undesirable effects is an aggravation of floods, particularly urban areas in the lowlands. Highland forests and wetlands have a strong link to floods in the lowlands. The destruction of the ecosystem for economic exploitation is important element in increasing of floods. Generally, rainfall in the highlands is more uniform spread throughout the year but there are evidences to suggest that slight increases in rainfall occur from the height of 400 m to 1,000 m above sea level, according to Abdul Rahim Nik (1996). Studies have shown that total water yield is affected by conversion and clearance of highland forests to other land uses.

Flooding characteristics are definitely affected by the removal of forest cover. According to Abdul Rahim Nik & Zulkifli Yusop (1999), there is scientific evidence which support the link between deforestation and flooding but only at local level within catchment of less than 50,000 ha. Increased landslides and flashfloods occurrences have been associated with widespread removal of natural forest cover in the highlands for the purpose of land use transformation. In most cases, flood flow increase is actually caused by soil compaction and reduces infiltration rather than vegetation removal (Balamurugan G. & Mohd Rizal Mohd Razali, 1999). Gassim et al. (1994) mentioned that flooding in was due to two factors; the morphology of the area and rapid growth development around the city, especially in the coastal area. Yaziz and Wan Nor Azmin (1984) reported that the frequency of flood peaks has increased with rapid urbanization in the Sungai Batu Catchment in and Sungai Klang Catchment in Klang.

7 2.4 Flood Frequency Analysis in Malaysia

Design flood estimation is an important task that is required in the planning and design of many civil engineering projects. Its purpose is to predict the magnitude of flood discharges of a river corresponding to a risk level that is acceptable to the design of structures. The risk is normally taken to be a probability of annual recurrence interval (return period). Many practicing engineers rely on rainfall intensities to generate flood peaks using a simple classical method called the rational method for flood estimations. The rational method is intended for very small basins, but it is common to be applied in some large basins without any modification. This poses a problem as the method does not take the pattern of any relation of physical law or forecasting or a hydrology cycle.

Lim and Lye (2003) uses index- flood procedure based on L- moments for regional flood estimation of ungauged basins in Sarawak, Malaysia. Two homogeneous regions were identified and the Generalized EXtreme Value and the Generalized Logistic distributions are found to describe the distribution of extreme flood events appropriately within the respective regions. A regional growth curve is subsequently developed for each of the regions. These curves can be used for the estimation of design floods in ungauged basins in Sarawak.

West Malaysia experience wet season beginning from October to the middle of January annually and usually flooding may occur within this period especially in low- lying areas. According to Muhammad Barzani et al. (1996), the flooding phenomenon has not only been restricted to the wet season and their frequency of occurrence has tended to increase. The monsoon, with wind dominantly from the south west and north east reaches West Malaysia resulting in hea:vy precipitation in the foothill regions and gradually change in precipitation intensity towards the coast in the south west. The moisture laden south westerly winds prevail from May to September, an inter- monsoonal period from late September to early November, and from November to March the north east monsoon sets in, followed by a second inter- monsoonal period until early May (Wong, 1974).

8 Flood frequency analysis of Semenyih Basin, was done using only 12 years of annual data, from 1969 to 1981. Flooding occur almost annually in the Hulu Langat area from 195 I to 1990. The highest big flood occurred in January 1971 which is classified as a catastrophic flood based on 15 years of frequency analysis. Influence of regional monsoon is most likely a more important factor for the occurrence of the 1971 flood in Semenyih Basin. Based on the return period of 15 years, the next big flood event would occur, but in 1986 most Asian countries were influenced by drought associated with the El- Nino phenomenon. No particular distribution is specified for the frequency analysis of Semenyih and Beranang Basin. However, plotted graphs of peak discharge versus the recurrence interval indicate that Weibull Plotting Position is used for the frequency analysis. The result could be used for construction of dams and other structures within the catchment area.

9 CHAPTER3 FLOOD FREQUENCY ANALYSIS

3.1 Introduction to Flood Frequency Analysis

Flood frequency analysis is used to predict design floods for sites along a river. The technique involves using observed annual peak flow discharge data to calculate statisti~al information such as mean values, standard deviations, skewness, and recurrence intervals. These statistical data are then used to construct frequency distributions, which are graphs and tables that tell the likelihood of various discharges as a function of recurrence interval or exceedence probability.

3.2 Return Period

The recurrence interval of flood is called return period which is defined as:

T= liP p-1 = (I)

Where, T = Return Period

P = Probability of recurrence of flood whose magnitude equal to or greater than specified magnitude, X

This represents the average intervals between the occurrence of flood of magnitude equal or greater than X. Thus if is stated that the return periods of a flood is 500 m3Is is 30

10 years at a certain station, it implies that on an average, the streamflow magnitude equal or greater than 500 m3/s occurs once in 30 years. However, it does not mean that every 30 years one such event is likely to occur. It is just a method of predicting. This concept is widely used for representation of flood frequency distribution.

3.3 Hydrological Frequency Distributions

Chow (1951) has shown that most frequency- distribution functions applicable in hydrologic studies can be expressed in the following equation known as the general equation of hydrologic frequency analysis:

Xr = x + KCJ' (2)

Where xr =value X of a random hydrologic series with a return period T, x =mean of the variate,

0' =standard deviation of the variate, K =frequency factor which depends upon the return period, T and the assumed frequency distribution

Standard error of estimate is defined as:

I

" A 2 L)x,-x,) 2 s = "'1-=.cl ____ (3) n

A Where x, =computed estimate of recorded event x,

11 The values of the annual maximum flood from a given catchment area for large number of years are called the annual series. This series is used to calculate the magnitude of flood that will occur in the projected years. For this study, the frequency distributions used will be limited to only six, which are: • Weibull Plotting Position • Log- Pearson III • Gumbel Type I • LogNormal2 • LogNormal3 • Pearson III

3.3.1 Weibull Plotting Positiou

This method ranked the order of the data in order to plot a graph. The data is arranged in descending order (from high magnitude to the lowest) and the probability, P, of each event being equaled or exceeded is calculated using the plotting position formula:

(4) p = ___!!!____ N+l

Where, M = order or number N =total number of events

Using the Wei bull formula, the recurrence interval, T;

T=_!_= (N+l) (5) p m

Using probability paper, graph Q vs Tis plotted of the above equation. The plotted point is then fitted to a best- fitting curve and the extrapolation is used to estimate the flood

12 magnitude of a specific return period. However, when large extrapolations of T are involved, the projected magnitude of flood will have high inaccuracy.

3.3.2 Log- Pearson III

If the logarithms, In x, of a variable x are distributed as a Pearson III variate, then the variable x will be distributed as a log- Pearson III with probable density function:

p(x)= 1 [lnx-y]p~te~[ln:~r] (6) ar(,B) a Where a, f3, y = parameters

r(p) = gamma function

To simplify the equation, this method will use equation as the basis equation. In this, the variate is first transformed into logarithmic form and then analyzed. The series of z variate, where

z =log x (7) Where x =variate of random hydrologic series

For this z series, for any recurrence interval T, the basic equation elaborate by Chow (1951) gives, (8)

Where K, =frequency factor which is a function of recurrence interval T and coefficient

of skew, Yt

a, =standard deviation of z variate sample

Yt =skew coefficient of variate z

13 = N_L(z- ,u,)' (9) (N -IXN- 2XuJ ,u, =mean of z N =number of years of record

The variations of Kz are given in Table 3-l

Table 3-1: Frequency Factors for Use in Log Pearson III Distribution

Coefficiem: Cumulative Probability, P, % of Skew yl so 80 90 95 98 99 Corresponding Return Period, T, Years

2 s 10 20 50 100

0.0 0.0000 .8416 I. 2816 1.6448 2.0537 2.3264 0.1 -.0167 .8363 1. 2917 1.6728 2. 1070 2.3997 0.2 -.0333 .8303 1.3009 1.6996 2.1595 2. 4727 0.3 -.0499 .8234 1.3089 1. 7254 2. 2112 2.5453 0.4 -. 0664 .8157 1.3159 l. 7501 2.2619 2.6172 0.5 -.0828 .8072 1.3218 1. 7735 2. 3117 2. 688~ 0.6 -.0990 • 7980 1.3267 1. 7958 2.3603 2.7588 0.7 -.1151 .7880 1.3304 1.8168 2.4078 2.8283 0.8 -.1310 • 7773 1.3330 1.8366 2. 454! 2. 89&8 0.9 -.1467 .7659 1.3345 l. 8551 2.4991 2.9641 1.0 -.1621 7537 1. 3349 l. 8723 2. 5428 3.0303 1.1 -.1772 .7409 1.3342 1.8881 2.5851 3.0952 1.2 -.1921 .7275 1. 3524 1. 9026 2.6260 3.1588 1.3 -.2067 . 7134 1.3295 ).9157 2.6653 3.2209 1.4 -.2209 .6987 1.3255 1.9274 2..7031 3.2816 LS -. 2347 .6834 1. 3204 1.9378 2.7394 3.3406 1.6 -.2482 .667<> I . 3! 43 1.9467 2. 7740 3.398l 1.7 -. 2612 .6513 1.3072 1.9543 2.8070 3.4538 1.8 -.2738 .6344 1.2990 1. 9604 2.8383 3. S07S 1.9 -.2860 .6171 1. 2897 1. 9651 2. 8678 3.5600 2.0 -. 2977 .5993 1.2795 1. 9684 2.8956 3.6103 *Source: Kite. 1988

14 3.3.3 Gumbel Type I

This extreme value distribution was introduced by Gumbel (1941) and is known as Gumbel's distribution. It is one of the most widely used probability-distribution functions for extreme values in hydrologic studies. According to his theory, the probability of occurrence of an event equal to or larger than a value Xo is (10)

in which y is a dimensionless variable given by

y = a(x-a) (II)

a = fix- 0.45005cr, (12)

a = 1.2825/ crx (13)

Y = 1.2825(x- Jlx) + _ 0 577 (14) (}X

Where fix =mean of maximum streamflow values, X

crx =standard deviation of the variate X

Rearranging Gumbel's equation, the value of the variate X with a return period T is (15)

Where cr,_1 =standard deviation of the sample size N

(16)

Yr = -[ln.ln-.-2:._] (17) T-1

Yn =reduced mean, a function of sample size Nand given in Table 3-2

S" =reduced standard deviation, a function of sample size N and given in Table

3-2

15 Table 3-2: Reduced Mean Yn and Standard Deviation S, in Gumbel's Extreme Value

Distribution

- SAMPLE MEAN, y, STANDARD SIZE, N DEVIATION, sn

10 0.4952 0.9496 15 0.5128 1.0206 20 0.5236 1.0628 25 0.5309 1.0914 30 0.5362 1.1124

35 0.5403 1.1285 40 0.5436 1.1413 45 0.5463 1.1518 50 0.548 1.1607 55 0.5504 1.1682

60 0.5521 1.1747 65 0.5535 1.1803 70 0.5548 1.1854 75 0.5559 1.1898 80 0.5569 1.1938

85 0.5578 1.1974 90 0.5586 1.2007 95 0.5593 1.2037 100 0.5600 1.2065

*Source: Kite, 1988

16 3.3.4 Log- Norma12

Murray R.Speigel (I 999) defined if the logarithms In x, of a variable x are normally distributed, then the variable x is said to be logarithmic- normally distributed such that

(I 8)

Where ,u y =mean of natural logarithms of x

crY =standard deviation of natural logarithms of x

Ify =In xis normally distributed, Eq. (3.2) can be written in terms of logarithms as:

lnxr = Yr = !ly + tcrY (19) Where t =standard normal deviate

Alternatively to avoid computation of the mean and standard deviation of logarithms, equation above can be modified: (20)

(21)

17 3.3.5 Log- Normal3

Just as the log- normal distribution represents the normal distribution of the logarithms of the variable x, log- normal 3 represents the normal distribution of the logarithms of the reduced variable (x-a) where a is a lower boundary. (Murray R.Speigel, 1999) The probability density distribution is then given by:

[lo(x~a)~",f (22)

Where ;.t Y =mean of natural logarithms of (x~a)

a =standard deviation of natural logarithms of (x~a) 1

If the lower boundary, a, is known then the reduced variable (x-a) can be used together with the procedures described for log- normal 2 distribution.

Condie ( 1973) has described a simple graphical method of determining the parameter a, which is applicable, provided that:

1. At least one of the graph scales, vertical or horizontal, is logarithmic

11. The curvature of the best fitting line is gradually decreasing

' --i

Figure 3-1: Graphical Technique of Estimating Parameter a

18 Referring to Figure 3-1, (*source: Kite, 1988), (x1, y1), (x2, y2), (x3, y3) are three points on the best-fitting line through the plotted event magnitudes (b-e) such that:

(XJ- Xt) = (X2- XJ) (23) 2 (24) a= YtYz- y, Yt + Yz -2y,

The T- year event, XT, is

fJ +!0' Xr :::;: a+ e Y Y (25)

3.3.6 Pearson III

The probability density distribution of Pearson III distribution is of the form

I [x-y]P-I -[x:r] (26) p(x)=-(/3)- e ai' a Where a,fJ,y =parameters

1(/J) = gamma function

If the substitution y = (x- y )I a is made, the equation 3.18 simplifies to (27)

Which is a one parameter gamma distribution described in many statistical texts.

, For the sample mean, fl , standard deviation, rr , and coefficient of skew, y1 the parameters a , f3 and y can be determined. Then,

f3 = (21 rJ (28) a= rr I .fjj (29)

r=fl-rrJ7i (30)

19 CHAPTER4 RAINFALL AND RIVERS IN SABAH AND SARAWAK

4.1 Rainfall in Sabah and Sarawak

Due to its more north-easterly location, Sabah is drier than Sarawak. The north-east coast suffers higher precipitation from December to January, whereas heavy rainfall occurs May to November on the west coast. The annual average rainfall is 2630 mm for Sabah and 3830 mm for Sarawak, with heavier precipitation recorded in the east coast of Peninsular Malaysia and the coastal regions of Sabah and Sarawak. The North-East Monsoon blows approximately from November to April bringing heavy rain to the east coast. From statistics, Sabah encounters rain half the number of days in a year. Most of the rains are of tropical rainstorms due to extremely high evaporation rate.

The seasonal variation of rainfall in Sabah and Sarawak can be divided into five main types:

a) The coastal areas of Sarawak and northeast Sabah experience a rainfall regime of one maximum and one minimum. While the maximum occurs during January in both areas, the occurrence of the minimum differs. In the coastal areas of Sarawak, the minimum obcurs in June or July while in the northeast coastal areas of Sabah, it occurs in April. Under this regime, much of the rainfall is received during the northeast monsoon months of December to March. In fact, it accounts for more than half of the annual rainfall received on the western part of Sarawak.

20 Forest reserve ooundEJry Rainfall AbO'VB 3500 mm Between 3000 mm and 3500 mm Bet>veen 2500 mm and 3000 mm .~ Bet'NE!on 2000 mm and 2500 mm N ' Between 1500 mm and 2000 mm Less than 1500 mm

Figure 4-1: Average Monthly Fall in Sabah *Source: The internet

In Sabah the rainfall intervals is 500 mm from 1000 mm to above 3500 mm, a fairly clear pattern of mean annual rainfall subjected to the geographic position and topographic features of Sabah can be found.

Generally, Sabah receives about 2500-3500 mm of rainfall annually. However, some localities obtained much lower or beyond this range due to influenced of coastal and in shadowed to large land-mass or ranges. The highest rainfall ranges, which is above 3500 mm, estimated only to cover I% of the state. The ranges distributed on small localised area of Mt. Kinabalu and (Ulu Moyog), north-eastern of Labuk Highlands and low-lying area in south-eastern of Klias plain. However, it may also believe to cover on other high elevated ground such as along peaks of mountain ranges and highlands.

22 ! 3'N

1 2"N 2'N

I"N

.w ";o,"'"'"" -a~ 110'[ 111'[ 112'[ 113'£ 114'[ Jl5'E

Figure 4-2: Isohyetal Map of Sarawak 2003 *Source: DID, Sarawak

In Sarawak, the total monthly rainfall varied from much below normal to much above normal. Sarawak, with an average rainfall of 5000 mm per year, is an expansive network of rivers, rainforests, , swamp forests and mountains. Annual rainfall varies between 3300 mm to 4600 mm for the greater part of the country.

Generally, , Samarahan, , Betong and divisions would get more rain than the other areas of Sarawak while and divisions would get the least amount of rain comparatively. Over Miri and Lim bang divisions, more rain would be expected during the inter-monsoon periods than the southwest monsoon period. This is because more frequent and heavier convective rain would occur in the afternoon and evening during the inter-monsoon period.

23 4.2 Rivers in Sabah and Sarawak

There are 176 total numbers of rivers in Sabah and Sarawak. Each state (Sabah and Sarawak) manages rivers in their respective states. The rivers consist of the main and . The is the longest river in Sarawak and Malaysia with a length of 760km located in northwest of . The (Sungai Kinabatangan) is the longest rivers in Sabah and it is the second longest river in Malaysia, with a length of 560 kilometers from its headwaters in the mountains of southwest Sabah, to its outlet at the , east of Sandakan.

Table 4-1: Rivers in Sabah and Sarawak

4.2.1 Sabah

There are 64 river systems in Sabah with 16 classified as major rivers in Sabah. There are 16 river basins in Sabah, with the Kinabatangan River basin on the East Coast as the largest basin, covering an area of 15,385 km'. The basin on the West Coast 2 covers an area of about 8,726 km • Most of the other basins cover comparatively smaller areas. In the table 4-2 next page shows 16 major rivers in Sabah and in the figure 4-3 shows a map of Sabah Rivers which includes the major rivers in each district, obtained from River Engineering of DID, Sabah

24 Table 4-2: 16 major rovers of Sabah in different district

Name of rivers District 1 Sg. Bengkoka Kudat 2 Sg. Kadamaian 3 SQ. Wario Kota Belud 4 Sg. Segama 5 Sg. Sugut 6 Sg. KinabatanQan Kinabatangan 7 SQ. Papar Papar 8 Sg. Padas Beaufort Sg. Membakutl 9 Mawao 10 Sg. Mesapol 11 Sg. Nabawan 12 SQ. KalumpanQ 13 Sg. Babagon 14 Sg. Pensiangan 15 Sg. Kiulu ! 16 SQ. Tamparuli Tamparuli!Tuaran *Source: Department of F1shenes, Sabah

, Rairlilll Sbhon /\I FINan> , '\I Fo!6Siti!GeM!-I:xl\.!ld

Figure 4-3: Map of rivers in Sa bah *Source: DID, Sabah

25 4.2.2 Sarawak

There are 112 river systems in Sarawak. The 760 km long Sungai Rejang is the longest river in the country. The river flows approximately 760 km to the . The upper part of Rajang River is also known as Batang Balui by the Orang Ulu. Malaysia largest and tallest (160m) hydro electric project, Bakun Hydro Electric Dam Project, is located on Batang Balui narrow Bakun Fall.

There are basically 22 basins in Sarawak. The biggest basins are upper Rajang Basin located in the division. is well known as hilly areas and the stream flow is very turbulence.

SARAWAI< ·~ RIVER BASINS For development planning purposes, !fie state ofsarawak Is divided into 21 ma}or rtver basl115.

South China Sea

Figure 4-4: Main rivers and basins in Sarawak

26 Table 4-3: Main Rivers and basins in Sarawak . NO. BASINS AREA NAME OF MAIN RIVER TOTAL 2 (KM ) COMBINED LENGTH OF. MAIN RIVER(S) (KM) 1 KAY AN 1,645 BATANG KAY AN 125 2 SG. SARAWAK 2,375 SUNGAI SARA W AK 120 3 SAMARAHAN 1,090 BATANG SAMARAHAN I 15 4 SADONG 3,550 BATANGSADONG 150 5 LUPAR 6,510 BATANGLUPAR 275 6 SARIBAS 2,200 BATANG SARIBAS 160 7 KRIAN 1,500 SUNGAI KRIAN 120 8 RAJANG Lower 47,880 BATANG RAJANG 760 Upper 9 OYA 2,195 BATANGOYA 240 10 2,275 BATANGMUKAH 205 1 I 2,510 BATANG BALINGIAN 160 12 5,260 BATANGTATAU 270 13 KEMENA 6,100 BATANG KEMENA 190 14 SIMILAJAU 660 SUNGAI SIMILAJAU 65 15 SUA! 1,540 BATANG SUA! 130 16 NIAH 1,280 SUNGAINIAH 105 17 SIB UTI 1,020 SUN GAl SIBUTI 80 18 BARAM 22,930 BATANG BARAM 635 19 LIMBANG 3,950 SUN GAl LIMBANG 275 20 TRUSAN 2,615 BATANGTRUSAN 205 21 LAW AS 1,050 BATANGLAWAS 75 *Source: DID, Sarawak

27 CHAPTERS FLOOD IN SABAH AND SARA WAK

Malaysia has along history of flooding, the country being exposed to monsoon winds and heavy conventional rainfall all year round rendering more than about I 0% of the country being flood-prone. The annual average rainfall is 2,630 mm for Sabah and 3,830 mm for Sarawak, with heavier precipitation recorded in the coastal regions of Sabah and Sarawak. Bulk of population in Sarawak and Sabah is concentrated in towns and villages in river valleys and coastal plains, hence prone to flood damages.

5.1 Flood event in Sa bah

In Sabah, floods are not a common occurrence because the average annual precipitation in the state is only 2,630 mm and is not widespread. Northern Sabah receives an annual rainfall of 2,800 mm and between 2,000 mm and 2,800 mm of rain falls at the foothills. The West and East Coasts of Sabah receive the most rainfall. Floods usually occur after a downpour in the low plains.

Figure 5-l: Flood in Kinabatangan, Sabah (1998)* *Source: The internet- Flood in Sabah

28 ,_...... '

SOUTH CHINA SEA

Figure 5-2: Flood prone areas in Sabah, Malaysia* *Source: Civil Engineering Program, School of Engineering & Information Technology, Universiti Malaysia Sabah

Flood prone areas in Sabah are shown in Figure 5-2. As shown in the figure, virtually every district in Sabah is affected by flooding to some extent but areas most affected are mostly in the West Coast with the exception of the Kinabatangan River in the East Coast. The severity of flooding in these areas varies from year to year and from river to river. The Department of Irrigation and Drainage monitor flood in the low-lying areas and compile annual records of such floods.

29 5.1.1 Flood Related Disaster in Sabah

Table 5-l: Flood related disaster in Sabah*

-Kampung Suasa Kampung Suasa (129 families) and Kampung -Kampung Logo Lago (81 families), in Beaufort. I people died drown in the tragedy. The government had allocated RM120 million to repair all damages. 2 Kinabatangan Feb,06 16 villages along Sg. Kinabatangan were affected by the big flood. 411 families were evacuated to temporary shelters. It is considered the worst flood as the water level was 3 meter above dangerous level. 2 Kudat place in some part town -Kudat town .110 families from three kampungs in Sikuati, -Sikuati Kudat, had to be sheltered at Sekolah Kebangsaan Lok Yuk in Sikuati 3 Dec,2006 194 families from four villages in Kota and Pitas were evacuated to flood relief centres in the districts 4 Kota Kinabalu July,2005 2, 793 families were affected by the big floods -Tuaran in Karambunai, Tuaran and Kota Kinabalu . -Karambunai Total ofRM1,402,500 worth of cash and food assistance were used to help the victims and repairing the utilities 5 Southwest Sabah Oct,2001 Heavy rains on 8th October 200 I over the west -Penampang coast of Sabah, Brunei and the northeastern -Papar coast of Sarawak caused flooding over low- -Beaufort lying areas of the districts of Beaufort, Papar and Penampang in southwest Sabah. Hundreds

30 of families were affected by the floods which caused several roads to be below l to 2 feet of water and disrupted rail services.

6 Kinabatangan Feb,2000 Continuous heavy rain for several days caused severe floods affecting 20 villages in , Sabah. About 4000 residents from 870 families were evacuated to safety while at least two people were drowned; nine houses were washed away while 14 others were badly damaged. According to the report, this was the worst flood since 1996.

7 57 areas in seven Jan,1999 The worst ever flood to hit Sabah happened on districts were 6th January 1999. More than 2,000 residents in affected, the seven districts were evacuated to temporary shelters. The heavy rain fell non-stop for ten leading with 22 hours resulting in a huge flood. Penampang was affected areas, worst hit by the flood. followed by Kota Kinabalu with 12 areas, Papar 10, Kota Belud 7, Tuaran 5, Beaufort 3 and 3. 8 Keningau Dec,1996 Storm Greg resulted in a huge flood in Other affected areas Keningau at the northeastern part of Sabah included Tuaran, resulting in the loss of many lives. Many of Papar, Kota those who died were Indonesians working in Kinabalu, that area. Pen am pang, Tawau and Sandakan.

31 *Source: Unusual weather events in Malaysia (2000) Daily Express, Sabah (2006)

There is estimated RM 130 million financial losses and 200 reported deaths, in December 1996 flood event (see to Table 5-2) (Chan, 1997). Prior to this situation, Sabah has played a part in the preparation of guidelines for developments, known as the 'Sabah Water Resources Master Plan', in the year 1995

Table 5-2: Official flood loss estimates for selected floods in Malaysia

Damage- ,p.cfS()ns Ftood event ($million Deaths evacuated (Ve~rL (Place) ____ ,__ at 1993 prk~.~L ·-·----~~-----~d' ·-- l ~lti'l KFi>lantan R, Ba~in '199.3 38 320,000 \9£7 Per ak R. Ri:lslo 15<\.5 0 2fi0,000 1\>fl"l Tf!H!':nggo:mu R i.lasifl 40.:> 17 78,(><)!) 19}"1 Patlanq R Bt-sin 93.1 24 153,000 "19T! KtM:~·Ia lumpur au 24 NA 23,R9H 1979 Pf!lni:ns.ulat Mal.a"{!ii~ NA 7 9.99:-l 1~);9? Peninsular Mnlaysla NA B 1983 Penin~ut~i Mat.ays.La NA 14 60,807 1Sli4 Batu p-,ahat R.. Basfn 20.3 0 8,400 19B£ Per~ insular Majaysfa NA 0 40,698 1988 P.f;!tlinsul;:~r MaJaysirJ NA 37 100,755 l9SB Kciant.a n R 81:U)in 330 19 36,800 "1988 :Sab;Jh NA 1 NA ~99! Pe:ninsullll' Malay5ia NA '11 Nfl 199'1 Peninstllcu M~(lt:~ys.ia NA 12 NA \CJS-::1 F~m~nswar Malnys.ia NA'J 22 11,000 1995 Pi;lnin~utar Malaysit~ NA 0 14,000 19% Sa bah ( )unr;} NA 9,fJOO 1991) S!1l!Bh (Dc~amoor) no.o" 200r: 15c000

Notfr:s; r.JA = MJt ovnilable , In tl!>lr1!J :':ithool ~(lf 8 total or betWeHn siX W 11 days b ThO Sabat~ ga•Jomrne·nt rjs,t1mah!U that dam01~ to roads, bridge~"· schools, power line>. go\lernnumt oftict~5 .mtf crtht!r ptlblit-utihhP--!i \Vtol!ld need at least RMl30 mll'lion to rcstore (TfUJ StCJr, 1 Jf.l.n!J;M'{ 1997). If pfivate­ plnpJ::rtlt).S. industrie'i. busir1e~ses.,. r;orp~ liv~tock. sllipping ves~h: and athe-r privately o~~ne(1 H'3$+1S(~; ~·.u:n~ Lfr>..cn inW account, the d

*Source: DID Malaysia, Malaysia National Security Council and local newspaper

32 5.2 Flood Event in Sarawak

In Sarawak flood season is known as "Landas". Most part of Sarawak affected by flood especially those located along big rivers. Sarawak experiences high rainfall of about 3850 3 mm annually and total annual surface water runoff is about 306 billion m . River courses are relatively short with steep gradients in upper stretches and comparatively flat and meandering stretches in the lower reaches. Flood flows are transient in upper reaches in duration and intensity towards the coastal plains.

Figure 5-3: Flood in Sibu *Source: Sibu Municipal Council (SMC)

Many parts of Sarawak experienced the most severe floods in recorded history during January and February 1963. During this period, the state experienced rainfall in amounts far greater than the normally high total for this time, and this was the major cause of the flooding. The long duration of rainfall and their high intensity contributed significantly to the seriousness of the flood situation.

33 Flood Duration: • 5 - l 0 days in • 3 - I 0 days in Lim bang & Law as Divisions • I 0 - 30 days in , Baram, Miri and Btg. Kemena regions • I 0 days in Mukah region • 40 days in Sibu (2 events, one with duration of I month and the other about I 0 days)

Flooding did not occur simultaneously throughout the country. Flood Damages Reported: • 800 longhouses badly damaged and destroyed. • 35,600 persons affected. • 4 persons died.

Recently, major floods of February 2003 and January 2004 that claimed to be the worst floods in 50 years in Sarawak, had Bau and surrounding area flood-stricken. Thousands of people were affected, and a lot of property damages.

Being a flood-hit area, Department of Irrigation & Drainage (D.I.D.) Sarawak is the regulating body that monitoring the hydrological data in the Sarawak Kanan River system. There are 2 river gauging' stations in Sarawak Kanan River, namely Buan Bidi station and Siniawan Station.

Buan Bidi gauging station is located upstream of Sarawak Kanan River, measuring the water level and indirect river flow through a developed rating curve equation. Siniawan gauging station is downstream, measuring only the water level. In between these two stations laid the town of Bau and several kampongs with approximate population of about 42,000. The area is left with little hydrological information to ponder with, thus indicated a need to reconstruct past flood events to have a better representation of the flooding scenarios in the mentioned area.

34 CHAPTER6 METHODOLOGY

6.1 Type of Data

According to Kite (1988), there ,are two ways in which data may be used in frequency analysis, The first method, direct frequency analysis, is to select from the total data only that information which is required in the design process, which is the maximum discharge in each year (annual series), The second method is to design mathematical model which will describe the observed hydrograph, This model can then be used to generate many sets of data to be abstracted,

For this project, the method used is direct frequency analysis, using annual maximum series of data ranging from 1965 to 2006. The annual series takes one extreme event from each year of the record. A major disadvantage of this technique is that the second or third highest event in a particular year maybe higher than the maximum event in another year, but is disregarded. But none the less, this method is used as it is very simple and requires direct application of data provided by Department of Irrigation and Drainage (DID) Malaysia,

6.2 Data Collection

The first step in carrying out flood frequency analysis· is to obtain the data series that is annual maximum discharge. The annual maximum series should be as long as the record allows. The greater the length of record the more certainty can be attached to the prediction of average recurrence interval.

35 The source of data is obtained from Hydrological Department, DID in both area that are Sabah and Sarawak. DID which responsible for all collection river discharge provides means for designers, researchers to obtain data easily from their database. To facilitate any river data, one has to fill a form either on-line or by personally come to office and no fee will be charged. On 7m February 2006, a letter of application for Softcopy streamflow data from earliest years available and the list of all related publications was faxed and send to both DID Sabah and Sarawak.

A reply was received from DID, Sarawak through email on 24th February 2006 attached with Water level data for 6 stations in Sarawak. On 28th of February 2006, the author received Discharge Rating Curves for 29 stations in Sarawak through fax for discharge calculation.

On 7'h March 2006 an email from DID, Sabah was received indicating that the author had to fax his application for the data using the form provided in their website. Furthermore, in the email includes the list of publication. On 21st March 2006, an email attached with softcopy data in term of daily mean discharge was received. The range of data applied is from 1965-2005. A letter was received on 3'ct April 2006 from DID, Sabah indicates that all of the application had been approved and an attachment of a list of station in Sabah.

With the aim of more comprehensive and good analysis, more data is taken from publications by DID, Sabah. However, published data is very limited starting from 1963- 1975. Any published data after 1975 were obtained from Hydrological Data published by DID, Malaysia though the number of Sabah and Sarawak stations in the publication were limited. The publications used for this project are: 1. Hydrologic Records of Sabah to 1968 2. Hydrological Records for Sabah 1969-1975 3. Hydrological Data- Streamflow Records 1975-1980 4. Hydrological Data- Streamflow Records 1980-1985 5. Hydrological Data- Streamflow Records 1985-1990

36 After making some comparisons, the author found that there's a large different of value 1 for maximum discharge. Thus, on 27 h April 2007, an email has been sent for data clarification. A reply was received through email on 30th April 2007 specify that the discharge values in the book were in term of maximum instantaneous and should not be compared with maximum values in the softcopy as the reading is for daily means. Thus, on 3'ct May 2007, a complete set of data for instantaneous maximum, minimum and average from earliest available until 2006 had been received through email. In this case, Mr. Ho Tsun Lin, Assistant Director for Hydrological and Survey Department in DID, himself advised the author to used the softcopy data for analysis.

The streamflow data are then place into Microsoft Excel for analysis. The graph of time (in year) versus discharge is then plotted. A sample of graph for station Sg. Padas at Kemabong, Sabah is shown in figure 6-1 below:

--+-Annual Average 111 Annual Flood ------Annual Drought

3000

2500

~ 2000 .§. :g. 1500 ~ .<:"' ~ 1000 iS 500

0 ~~ ~ ~~ ~ ~ ~.~ ~.~ ~--~.~ ~.~ ~ ~ ~ ~-- ~ ~ ~ ~ ~- ~ ~ ~ ~ ~ ~ ~

oomo~N~V~~~oomo~NMV~ID~OOmo~NMV~ID~OOmO~NMV~ID mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmooooooomw~~~~~~~~~~oooororooooooooororommmmmmmmmmooooooo ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~NNNNNNN Year

Figure 6-1: Graph of Time versus Discharge for Sg. Padas at Kemabong (1969-2006)

For each river station, the detail of description obtained from the publications by DID is extracted and included as part of the research (refer figure 6-1 for station at Sungai Padas

37 at Kemabong, Sabah). It includes the location of the site, its catchment area, elevation and catchment characteristics (shape, topography, vegetation, soil cover and rock type).

Station No. 4959401 SUNG AI PAD AS AT KEMABONG Gauging site:- 130m cableway Longitude & Latitude: -115"55'15" E 04"55'00" N. Catchment Area:- 3185km2 Elevation above mean sea level:- 183 m

Catchment characteristics:~ (a) Shape:- The maximum length and breadth of the catchment are 90 km and 55 km respectively (b) Topography:- Mountainous with elevation up to 2000m (c) Vegetation :- Virgin and secondary jungle with some shifting cultivation (d) Soil Cover:- Sandy learns 204m deep (e) Rock Type: - East side of catchment: sandstone, mudstone. West side of catchment: siltstone shale, massive sandstone.

Ranged of observations:- The range of river stages observed is from 18.93m to 26.42m

Figure 6-2: Description of river station (Sungai Padas at Kemabong, Sabah) provided by DID

All of information regarding mean annual discharge, average maximum and minimum and absolute maximum and minimum discharge is summarized in a table.

38 Table 6-1: Information on discharge of river station - Sg. Padas at Kemabong

Sungai Padas at Name Kemabong 2 Area (km ): 3185 Elevation (m): 183 Average Rainfall (mm) Water Use Total Mean yearly (m 3/s): 113.77 Mean of"Min"s yearly (m3/s) 13.0 Mean of"Max"s yearly (m3/s): 1296.3 Absolute Min, yearly (m 3/s): 2.74 Absolute Max yearly (m 3/s): 2404.2 Hydrological Records for Sabah, 1968-1975, DID Sabah Source Softcopy, Annual Average. Instantaneous Minimum and Maximum, DID, Sabah

The table includes the catchment area, elevation, average rainfall and water use (provided by DID) and other information on rivers discharge. Table 6-1 is available in Appendix for all river station analysed.

6.3 Choice of Stations

In the figure 6-3 next page, shows the location of river stations in Sabah. In the first figures location of all river stations exist in Sabah. The pink circle represents the river stations chosen for the analysis while the blue triangle indicates the river stations not analysed due to insufficient data. In the figure 6-4 shows water level stations in Sabah. Most of water level stations in Sarawak located at the south of the state and only 5 stations have a sufficient and reliable data for the analysis.

39 LEGEND River stations analysed •... River stations not analysed

Figure 6-3: River Stations Analysed in Sabah

40 5' - SARMWAK RAil\! r-ALL. E'v'APOR.O.TOt~. SU t.ISI-IIhl E .O.hl D 1-1 U Y 10 1TY ST.O.T~hiS- 1998 -,..._ -- h ...... _-...... _l __ -• .....-. .... -wr CliJ -...... -.....-...... -...... -...... _ - ,;o-.•"' ""·-·- :.;:V. c.~ #

._,. _g .. ~-__...... ,_ ,..... _...... ~ ...... -...... -CI·~E' C'll

....._. = = .... _.. ····- ...... ,__., ..... ·~· ·~· .;/.!, LIIJIA liT A It ·~· •

9899P,[bg999RF' ·~· ·~· • • ·~· Figure 6-4: River Stations in Sarawak

4! Table 6- 2: Number of stations in Sabah and Sarawak

Overall only 34% of stations in Sabah and Sarawak have been analysed. For Sabah, the total numbers of stations are 44 and there are 37 stations with sufficient data to be analysed. All of the annual data are obtained from softcopy. 7 more stations are not included in analysis due to insufficient amount of annual data from the stations. The reasons for the lack of data are mechanical failure of the gauge, inaccessibility, flood, damage to the recorder and human error. In order to obtain good result for flood frequency analysis, the minimum amounts of data required are I 0 years which is equivalent to I 0 maximum streamflow or flood data. Such stations with more than I 0 years should produce more accurate result and the probability to obtain the highest flood magnitude for the duration will be larger.

There are 79 water level stations in Sarawak. Since all of the data provided by the authority are in term of water level, calculation is required to convert them into discharge. The authority provides specific Rating-Curve for each station. Only 29 stations in Sarawak do have rating curve and only 5 stations are usable for the analysis. The flood stages for these 5 stations are still in the effective range of the Rating-Curve. For other remain stations, most of the flood stages are out of effective range of the Rating-Curve given thus flood flow are unable to determine. The list of stations with Rating Curves is shown in the appendix B.

42 The annual discharges are taken from available data from 1965-2006. Though, there are no stations with complete 40 annual data the annual maximum data available are 38. Some of the data are incomplete which has some unknown values in particular year. This will cause inaccuracy in the result as the years with no flood data may have the highest flood of the study period (40 years). The number of river stations for both states in Sabah and Sarawak with specific amount of data is shown in Figure 6-5:

~a1nge of 10-20 (37 %)

15 stations

Figure 6-5: No of stations with range Yearly Data

6.4 Analysis of Annual Maximum Discharge Data

Flood frequency analysis is a statistical method to analyse flood data, which involves many formulas and graph. To enhance the misunderstanding of frequency analysis, manual calculations are done to calculate the return period of discharge for some stations. After proper understanding, it will be easier to analyse the data. To ease the process, software called DISTRIB is used to obtain a more accurate result. This software was developed by Dr. Saied Saiedi (1989), which uses QBasic to obtain the streamflow for many return periods.

43 Users are required to enter the type of data, number of data to be analyzed, the return period required and the streamflow data as the input of the programme. DISTRIB will then compute the sum, mean, standard deviation, skew coefficient and variation coefficient of the data and the log of the data (for log- type distributions). The output of the programme will be the projected streamflow for the specified return period. The distributions computed by DISTRIB are the normal distribution, log- normal 2, Gumbel type I, log- Pearson III, log- normal 3, Pearson III and plotting position formula (Weibull). The analysis includes the standard error of each distribution, which is taken as the basis to choose the two best fit distribution of the result. A sample of DISTRIB output is attached in the Appendix B, for Sungai Tawau at Kuhara, Sabah. Note that for this project, the distributions used are limited to Log-Normal 2, Gumbel Type I, Log-Pearson Ill, Log-Normal 3, Pearson III and Weibull Plotting Position.

DISTRIB could analyze a minimum of 10 data. Thus, stations of less than 10 years maximum streamflow data will be disregard. Out of the 44 river stations, only 39 stations have the significant number of data, ranging from 10 to 40 years of annual maximum flow.

Two best- fit distributions will be chosen based on the computation of the distribution standard error. The distributions with two lowest errors are taken as the two best fit distributions to be further analyzed in the discussion.

44 CHAPTER 7 RESULTS

7.1 Description of results

Table 7-1 and 7-2 in the next page shows stations with streamflow data received by the authority for both states. The detailed information on the river is described in table 7-3 and 7-4 for Sa bah and Sarawak. It contains the catchment characteristic and information run off of the river station.

The results of flood frequency analysis are summarized in table 7-5 and 7-6 for Sabah and Sarawak. This table describes the river name along with the total mean (m 3/s), the estimated flood for selected return periods from 5 to I 0,000 years and the two best fit distributions from the analysis. The table is crucial in analyzing the result of findings.

A short summary of each river (location and characteristic) is described in the Appendix C. The summary is given by DID Sabah. The graphs of annual discharge of each river are plotted on streamflow discharge (m 3/s) vs. time (year) axis. The second graph is the frequency analysis of annual floods of the river. After the data had been run in DISTRIB, the result obtained is plotted in a graph to describe the differences in the output data. The distributions are plotting position (Weibull), Log- Pearson, Gumbel Type I, Log- Normal 2, Log- Normal 3 and Pearson III.

45 able 7-1 Summary of River Stations in Sa bah

>TN. NUMBER NAME OF STATION PERIOD OF DATA REMARKS NOTES ll 4278402 SG. TAWAU di KUHARA 1983 - 2006 ANALYSED - 4278403 SG. TAWAU di JAMBATAN PUTIH 1994 - 1999 closed NOT ANALYSED - 4378401 SG. TAWAU di LADANG IMAM 2000 - 2006 NOT ANALYSED - 4381401 SG. BALUNG di BALUNG BRIDGE 1992 - 11/2006 ANALYSED 4474401 SG. di KALABAKAN 11/2006 - 1986 - ANALYSED - 4581401/2 SG. KALUMPANG di MOSTYN BRIDGE 1969 - 09/2006 ANALYSED - 4764401 SG.SAPULUTdiSAPULUT 1990 - 2006 ANALYSED - 4764402 SG. TALANKAI di LOTONG 1993 - 2006 ANALYSED - 4955403 SG. MENGALONG di 1983 - 2006 ANALYSED - 4959401 SG.PADASdiKEMABONG 1969 - 2006 ANALYSED - 5074401 SG. KUAMUT di ULU KUAMUT 1969 - 2006 ANALYSED _, 5156403 SG.LAKUTANdiMESAPOL 1994 - 2006 ANALYSED _, 5159401 SG. PADAS di 1969 - 1985 closed ANALYSED -! 5181401 SG. SEGAMA di LIMKABONG 1978 - 10/2006 ANALYSED - 5261401 SG. PEGALAN di ANSIP 1969 - 2006 ANALYSED _, 5261402 SG. SOOK di BlAH 1969 - 2006 ANALYSED - 5275401 SG. KINABATANGAN di PAGAR 1986 - 2006 ANALYSED - . 5357403 1981 2006 SG. PADAS di BEAUFORT JPS - ANALYSED - 5373401 SG. MILIAN di TANGKULAP 1969 - 2006 ANALYSED - 5375401 SG. KINABATANGAN di BALAT 1978 - 2006 ANALYSED - 5461401 SG. BAIAYO di BANDUKAN 1993 - 2006 ANALYSED -· 5462402 SG. APIN-APIN di WATERWORKS 1996 - 2006 ANALYSED - 5465401 SG. LABAU di SINUA 1993 - 2006 ANALYSED - 2006 5668401 SG. KEGIBANGAN di TAMPIAS P.H. 1997 - ANALYSED - 5760401 SG. PAPAR di KAIDUAN 1969 - 2006 ANALYSED - 5760402 SG. PAPAR di KOGOPON 1969 - 2006 ANALYSED 5768401 SG. LABUK di TAMPIAS 1977 - 2000 closed ANALYSED - 5768402 SG. LIWAGU di MARINGKAN 1997 - 2006 ANALYSED 5872401 SG. LABUK di POROG 1969 - 2000 No gauging after 2000 ANALYSED - 5872402 SG. LABUK di 2001 - 2006 NOT ANALYSED 5961401/3 SG.MOYOGdiPENAMPANG 1969 - 2006 ANALYSED - 6065401 SG. LIWAGU di 1993 - 2006 ANALYSED - 6073401/2 SG. TUNGUD di BASAl 1969 - 2006 ANALYSED - 6162401 SG. TUARAN di MALANGGANG 1969 - 1982 closed ANALYSED - 6162403 SG. TUARAN di P.H. N0.1 1982 - 2001 closed ANALYSED - 6162404 SG. TUARAN di TAMPARULI 2001 - 2006 NOT ANALYSED ·6172401 SG. SUGUT di BUKIT MONDOU 1984 - 2006 ANALYSED - 6264401 SG. KADAMAIAN di TAMU DARAT 1969 - 2006 ANALYSED - 6364401 SG. WARIU di BRIDGE N0.2 1969 - 2006 ANALYSED - 6468402 SG. BONGAN di TIMBANG BATU 1988 - 2006 NOT ANALYSED - 6670401 SG. BENGKOKA di KOBON 1972 - 2006 ANALYSEJ - 5966401 SG. LIWAGU di BEDUKAN 1970 - 1980 ANALYSED .. - 5770401 SG. LABUK di TOMBOLOI 1969 - 1976 NOT ANALYSED- - 6467401 SG. SANDAU di SIMPANGAS 1969 1976 NOT ANALYSED - Total Stations 44 - Total Stations Analysed 37 - 46 Table 7-2· Station with Data received by DID Sarawak '

No Stn Number Station Name River Name River Basin Period of Data 1 1004438 Krusen Kayan Sungai Sadong 1983-2006 2 1005447 Meringgu Ketup Sadong 1981-2006 ' 3 1006403 Sg. Bedup Bed up Sa dong 1977-1985 4 1018401 Lubok Antu AI Lupar 1977-2006 5 1105401 Serian Sadong Sadong 1962-2006 6 1108401 Saba! Kruin Saba! Kruin Sadong 1988-2006 7 1114415 Sg. Entulang Entulang Lupar 1984-1985 8 1114422 Entulang D Entulang Lupar 1980-2006 9 1204441 Ma'ang Serin Samarahan 1983-1991 10 1210401 Tuba Lupar 1987-2000 11 1301426 Boring Sarawak Sungai Sarawak 1970-1997 12 1301427 Buan Bidi Sarawak Kanan Sungai Sarawak 1981-2006 13 1302428 Gil Sarawak Kiri Sungai Sarawak 1975-2006 14 1304439 Batu Gong Tuang Samarahan 1976-2006 15 1310401 Mintu, Kuala Mintu Lupar 1995-2006 16 1316401 Entaban Skrang Lupar 1988-2006 17 1415401 Lubau , Nanga Layar Sari bas 1990-2006 18 1601401 Rayu, Sg. Rayu Sungai Sarawak 1992-2006 19 1714402 Wong Bernet Krian Krian 1982-2006 ' 20 1813401 Sebatan Sebatan Krian 1983-2006 21 1826401 Mukeh, Ng. Katibas Lower Rajang 1979-2001 22 1932408 Telok Suing Balleh Upper Rajang 1984-2001 23 2130405 Benin, Nanga Rajang Upper Rajang 1981-2005 24 2421401 Stapang Oya Oya 1988-2005 25 2737413 Be lag a Rajang Upper Rajang 1975-2005 26 2837401 Sg. Belaga Be lag a Upper Rajang 1984 27 3152408 Lio Matu Baram Baram 1975-2005 28 3231401 Sibiu ATC Sibiu Kernen a 1983-2002 29 3541410 Jegan, Long Tin jar Baram 1967-2005 30 3946411 Terawan, Long Tutuh Baram 1982-2005 .31 4448420 lnsungai, Nanga Lim bang Lim bang 1977-2005 32 4450401 Lubok Lalang La lang Limbang 1989-1996

47 Table 7-3· Detailed Information of Rivers in Sabah Number Geographical Characteristic Catchment Characteristic o... Runoff Info Rainfall Info Annum Pavg(nun) No St. No Name of Name of Length of Elevation Catchment No of Data y,~ Annual Flood, Q ( m3/s) S

3 4378401 Sg. Tawauat Sg. Tawau 7 00-06 4.42 1.83 47.84 0.81 62.3 8.27 17 1500 Ladang Imam 4 438140! Sg. Balung at Sg. Balung 15 94-06 3.93 0.52 83.48 O.Q{j 213.19 50.27 60 3000 Balung Bridge 5 447440! Sg. Kalabakan Sg 21 86-06 32.63 1.69 695.56 0.53 1401.2 398.46 57 2500 at Kalabakan Kalabakan .

6 4581401 Sg. Kalumpang Sg. 55 544 37 69-06 22.37 4.02 681.78 0.1 1820.1 458.32 67 2500 at Mostyn Kalumpang Bridge

7 4764401 Sg. at Sg. Sapulut 17 90-06 76.67 I 1.78 900.31 4.89 1836.6 340.7 38 3500 Sapulut 8 4764402 Sg. Talankai at Sg. Talankai 14 93-06 21.48 4.19 349.72 0.75 581.78 141.14 40 3500 Lotong 9 4955403 Sg. Menga1ong Sg 23 83-06 27.21 2.2 552.35 0.14 889.98 249.62 45 3500 at Sindumin Mengalong

10 4959401 Sg. Padas at Sg. Padas 183 3185 38 69-06 113.77 13 1296.53 2.74 2404.2 438.97 34 3000 Kemabung

II 5077401 Sg. Kuamut at Sg. Kuamat - 30 2950 38 69-06 122.66 8.2 1956.92 2.31 4121.3 856.1 44 3000 Ulu Kuamut 12 5156403 Sg. Lakutan at Sg. Lakutan 10 316 21 69-06 9.45 1.08 434.62 0.2 1388.3 267.69 62 3000 Mesapol 13 5159401 Sg. Padas at Sg. Padas 168 7718 17 69-85 182.33 25.63 1633.2 4.95 4730.1 1204.98 73 2000 Tenom 14 5181401 Sg. Segama at Sg. Segama 2450 29 78-06 101.86 14.11 977.73 1.53 2063.3 414.05 42 2500 Limkabung 15 5261401 Sg. Pega1an at Sg. Pegalan 230 2175 38 69-06 52.03 10.78 400.57 1.96 1379.6 236.9 59 3000 Ansip ······················ 16 5261402 Sg. Sook at Sg. Sook - 260 1684 38 69-09 24.53 2.25 180.72 0.39 357.49 73.61 41 3000 Biah 17 5275401 Sg Sg - 21 86-06 35">.41 35.64 1510.87 4.25 2004 335.71 22 3000 ~ Kinabatangan Kinabatanga at Pagar 0 . -··- Table 7-3· Detailed Information of Rivers in Sabah Number Geographical Characteristic Catchment Characteristic Delli Runoff info Rainfall Info Annwti Pavg(mm) No St No Name of Name of Length of Elevation Catchment No of Data Yo~ Annual Flood, Q ( m3/s) Std Coeff of Station River River (km) k~ Variation (m) (km2) Total Mean Mean of Mean of Absolute Absolute Deviation (%) "Min"s "Max"s Min M~ 5357403 Sg. Padas at Sg. Padas 16 81-06 220.43 24.13 960.29 1.04 1535.4 256.03 27 3500 " Beaufort JPS 19 5373401 Sg. Milian at Sg. Milian 25 5730 38 69-06 227.55 24.09 1085.3 2.79 2413.6 355.91 33 3500 Tangkulap 20 5375401 Sg Sg 563 2l 10800 29 78-06 406.17 48.37 1681.52 7.49 3611.6 571.55 34 3500 Kinabatangan Kinabatanga at Balat n 21 5461401 Sg. Baiayo at Sg. Baiayo 14 93-06 5.95 1.48 55.15 0.08 92.39 22.11 40 3000 Bandukan 22 5462402 Sg. Apin- Apin Sg. Apin- II 96-06 4.14 0.8 89.98 0.22 160.62 41.88 47 3000 at Waterworks Apin

23 5465401 Sg. Labau at Sg. Labau - 14 93-06 5.52 0.87 254.51 0.3 538.28 114.22 45 2500 Sinua 24 5668401 Sg Sg 10 97-06 44.12 8.49 568.19 2.4 709.92 71.65 13 3000 Kegibangan at Kegibangan Tampias 25 5760401 Sg. Papar at Sg. Papar 91 357 37 69-06 24.24 3.48 438.24 . 0.86 1550.6 251.44 57 3000 Kaiduan 26 5760402 Sg. Paparat Sg. Papar - 24 536 37 69-06 43.18 6.48 814.13 1.33 2477 389.07 48 3000 Kogopon 27 5768401 Sg. Labuk at Sg. Labuk 168 2010 24 77-00 105.65 21.37 1270.34 L77 2882.9 672.87 53 3500 Tampias 28 5768402 Sg. Liwagu at Sg_ Liwagu 10 97-06 37.05 8.09 284.64 2.4 395.68 77.01 31 3500 Maringkan 29 5770401 Sg. Labug at Sg. Labuk 98 2460 8 69-76 I 18.2 21.61 1404.81 11.8 2774 684.21 49 3000 Tomboloi 30 5872401 Sg_ Labukat Sg. Labuk - 17 3240 32 69-00 185.76 37.16 1806.34 4.1 3534.4 836.5 46 3000 Porog 31 5872402 Sg. Labuk at Sg. Labuk - 6 2000-2006 125.82 28.63 1037.2 24.79 1497.2 279.2 27 3000 Telupid 32 596!401 Sg. Moyogat Sg. Moyog 38 69-00 14.9 13 295.76 0.21 507.28 81.09 27 2500 Penampang 33 5966401 Sg. L1wagu at Sg. Liwagu 430 440 II 70-80 4.96 0.49 82.55 0.01 298.67 80.46 95 2500 Bedukan 34 6065401 Sg. Liwagu at Sg. Liwagu - 14 93-06 0.57 0.12 22.32 0.06 91.34 22.23 100 2500 Kinaba\u Park 35 6073401 Sg. Tl.lllgud at Sg. Tl.lllgud 24 700 38 69-06 43 4.37 782.24 0.89 1516.8 359.73 46 3000 Basai 36 6162401 Sg. Tuaran at Sg. Tuaran 45 546 14 69 82 43.48 4.69 1202.45 0.16 3040.2 681.21 57 2000 Malanggang \,( 37 6162403 Sg. Tuaran at Sg Tuaran 45 639 20 82-01 34.05 -- 3.75 427.6 0.81 902.89 \83.57 43 2000 P.HNo.l Table 7-3· DetaHed Information of Rivers in Sabah Number Geographical Characteristic Catchment Characteristic Do

41 6364401 SgWariuat Sg_ Wariu 37 243 38 69-06 18.58 2.66 551.95 0_63 1457_7 185.36 34 2000 Bridgeno_2 42 6467401 Sg_ Bandau at Sg. Bandau 40 228 8 69-75 11.24 0_95 109733 0.2 2333 637.05 58 2500 Simpangas 43 6468402 Sg. Bongan at Sg. Bongan - 19 88-06 15.08 2.48 470.4 0.81 19962 500_85 106 2500 Timbang Batu

44 6670401 Sg. Bengkoka Sg. 38 69-06 24.48 2.53 602.99 0.\l 1631.3 398.45 66 2500 at Kobon Bengkoka L__ L_ - - ---

Vl 0 Table 7-4· Detailed infonnation of Rivers in Sarawak GEOGRAPHICAL CATCHMENT DATA RUNOFF INFO Rainfall Info CHARACTERISTIC CHARACTERISTIC Annual Flood, (m'ls) Annuru Std Coeff Pavg(mm) No. StnNo Name of Name of Length of Elevation Catchment No ofdat Y= Total Mean Mean of Mean of Absolute Absolute Variation Stn station river "Min"s "Max"s (%) river(km) (m) "'" Min M~ (km'l I 1005447 Sg. Ketup . 338.2 24 81~05 19.94 3.57 78.99 0.31 119.61 14.01 18 4220

I 46 9 77~85 3.13 0.65 32.86 0.43 60.56 14.47 24 3850 Bedup 2 1018401 _ Sg. Ai . 26 1304.7 29 77-{)5 I24.52 27.78 425.86 1.39 682.77 135.45 32 3850

5t . 3 1105401 ~~~ Sg. Kotup 150 950.5 42 62~05 56.81 5.25 266.49 0.33 392.04 62.29 23 3850

! ·'" o. -v, 4 1114415 Satang Sg. Entulang 50 43.8 2 84-85 131.05 12.75 2482.55 I 4784 1187.79 48 3150 Entulangat Entulang 121040- Sg. Sebuyau 28.5 24 87-00 2.69 0.75 7.88 2.64 10.39 1.55 20 3500

5 1301426 Sg. P~il ~: Sg. Pedil . 123 9 77~85 15.98 1.97 384.59 0.17 589.1 94.58 16 3850 Boring 6 1301427 Sg. Sarawak Sg. Sarawak 120 16.74 217 5 81-85 182.33 2.47 274.91 2.47 390.1 1204.98 73 4220 Kanan at PekanBuan K"'"' Bidi 7 1302428 Sg. Sarawak 120 . 425 13 77-90 33.01 8.18 468.81 0.06 866.33 187.58 40 4220 Kin

8 1813401 Sg. Sebatan Sg. Sebatan 50 33 5 81~85 1.06 0.04 9.97 0.01 13.76 3.57 36 3500 at Sebatan 9 2130405 Sg. Rajang a Sg. Rajang 760 50 21192 9 81-90 1429.53 113.15 4329.53 1.61 6385.64 2256.95 35 3850 Ng Benin 10 2737413 Sg. Rajang a Sg. Rajang 760 50 18190 5 81~85 1343.5 203.46 6147.9 146.79 7610.5 913.8 12 3850 Belaga II 2837401 Sg. Belaga at Sg. Belaga 50 2503 I 84-85 . . . . . 4200 Long Bangan 12 3946411 Sg. Tutohat Sg. Tutoh 18.3 3210 6 82-87 214.98 44.41 636.44 2.6 961.52 252.85 40 4200 Long - Terawan Table 7-5 Summary of Results Obtained From Flood Frequency Analysis of Annual Flood in Sabah Total Mean No Of Return Period (year)

2 Coeff. of No Name of Station Area(km ) 3 Two Best Fit Distributions (m /s) Yearly Data Variation(%) 5 10 20 50 100 1000 10000 Estimated Floods (m3/s) Sg. Tawau at 104 3 38 Gumbel Type Log-Pearson I Kuhara 56 40 51 60 73 83 115 146.52 I III Sg. Balung at 4 15 Log-Pearson 2 Balung Bridge 60 Il6 I49 182 224 256 364 475 Pearson III III Sg. Kalabakan at 33 21 Log Pearson Gumbel Type 3 Kalabakan 57 1060 1290 1472 1661 1772 1955 2123 lli I Sg. Kalumpang at 544 22 38 Gumbel Type Log-Pearson 4 Mostyn Bridge 67 942 1242 1528 1900 2178 3098 4016 I III Sg. Sapulut at 77 17 Gumbel Type Log-Pearson 5 Sapulut 38 1187 1465 1731 2074 2328 3182 4042 I III Sg. Talankai at 21 I4 Log-Pearson 6 Lotong 40 464 532 585 642 678 775 848 Pearson III 111 Sg. Mengalong at 27 23 Log-Pearson 7 Sindumin 45 775 883 963 1045 1094 1215 1297 Pearson III 1ll Sg. Padas at 3185 114 38 Gwnbel Type Log-Pearson 8 Kemabung 34 1661 1974 2222 2577 2843 3722 4600 I lli Sg. Kuamut at Ulu 2950 123 38 . Gumbel Type 9 Kuamut 44 2688 3226 3761 4454 4973 6687 8399 I Log-Normal 2 Sg. Lakutan at 316 9 21 10 Mesapol 62 573 762 963 1240 1460 2236 3074 Pearson III Log-Normal 2 Sg. Padas at Tenom 7718 182 17 II 73 1438 2144 2946 4116 5058 8610 12654 Pearson III Log-Normal2 Sg. Segama at 2450 102 29 Gumbel Type 12 Limkabung 42 1331 . 1607 1871 2213 2470 3316 4161 I Log-Normal 2 Sg. Pegalan at Ansi 2175 52 38 Log-Pearson 13 59 520 673 845 1112 1351 2441 4199 Ill Pearson Ill Sg. Soak at Biah 1684 25 38 Gumbel Type I4 4I 242 290 336 395 440 587 735 I Pearson III Sg. Kinabatangan a 352 21 Gumbel Type 15 Pagar 22 1457 1721 1947 2208 2388 2914 3372 Pearson III I Sg. Pa:das at 220 16 Gumbel Type Log-Pearson 16 Beaufort JPS 27 1182 1354 1518 1732 1892 2420 2947 I 111 Sg. Milian at 5730 228 38 Gumbel Type 17 33 1380 1613 1835 2123 2388 3052 3763 I Log-Normal 2 ' Tangkulap Sg. Kinabatangan at 10800 406 29 Gumbel Type 18 Jluiat . 34 2044 2424 2803 3306 3690 4992 6338 Pearson III I ·--· ·-- Total Mean No of Return Period (year)

2 Coeff of No Name of Station Area (km ) 3 Two Best Fit Distributions (m /s) Yearly Data Variation(%) 5 10 20 50 100 1000 10000 Estimated Floods (m3/s) Sg. Baiayo at 6 14 Gumbel Type 19 Bandukan 40 71 88 105 126 142 179 195 I Pearson III Sg. Apin- Apin at 4 11 Gumbel Type 20 Waterworks 47 !00 126 !52 184 209 290 372 I Log-Normal 2 Sg. Labau at Sinua 6 14 Gumbel Type 21 45 340 430 517 630 713 992 1273 I Log-Normal 2' Sg. Kegibangan at 44 10 Log-Pearson 22 Tampias 13 614 650 682 719 743 817 884 Ill Pearson III Sg. Papar at 357 24 37 Log-Pearson 23 K.aiduan 57 574 751 935 1189 1388 2089 2842 Pearson Ill Ill

Sg. Papar at 536 43 37 Log-Pearson j 24 Kogopon 48 1023 1297 1582 1977 2286 3374 4544 Pearson III III ' Sg. Labuk at 2010 106 24 Gumbel Type 25 Tampias 53 1858 2313 2750 3314 3738 5136 6533 I Pearson III Sg. LiWagu at 37 10 Gumbel Type Log-Pearson 26 Maringkan 31 310 366 418 490 538 707 876 I Ill Sg. Labuk at Porog 3240 !86 32 Gumbel Type 27 46 2513 3065 3595 4280 4794 6491 8185 I Pearson III Sg. Moyog at 15 38 Gumbel Type 28 Penampang 27 364 418 470 535 585 750 914 I Pearson III Sg. Liwagu at 440 5 11 Log-Pearson Gumbel Type 29 Bedukan 95 129 202 289 427 550 1082 1826 lli I Sg. Liwagu at 1 I4 Gumbel Type 30 Kinabalu Park 100 33 50 65 90 109 176 249 Pearson III I Sg. Tungud at Basai 700 43 38 Log-Pearson 31 46 1086 1286 1506 1649 1775 2108 2347 Ill Pearson III Sg. Tuaran at 546 43 14 Gumbel Type 32 Malanggang 57 1817 2331 2826 3464 3933 5521 7120 I Log-Normal2 Sg. Tuaran at P.H 639 34 20 Gumbel Type 33 No.l 43 593 720 842 999 1117 1508 1898 I Pearson III Sg. Kedamaian at 6 6 Log-Pearson 34 Tamu Darat 43 1124 1303 1455 1630 1750 1999 2372 Pearson III III Sg. Wariu at Bridge 2150 80 23 Gumbel Type 35 no.2 45 754 912 1064 1261 1408 1895 2381 I Log-Normal 2 ~g. Bongail. at 15 19 36 i 4'imbang Batu 106 782 ll32 1491 1981 2362 3_685 5089 Pearson III Log-Normal 2 Sg. Bengkoka at 24 38 Gumbel Type 37 Kobon . 66 940 1186 1422 1727 1956 2711 3466 I Pearson Ill ·---- Table 7-6· Summary of Results Obtained From Flood Frequency Analysis of Annual Flood in Sarawak Total Mean No of Return Period (year) Name of 2 Coeff. of No Area (km ) (m"ls) Yearly Data 5 !0 20 50 100 1000 10000 Two Best Fit Distributions Station Variation (%) I I I I I I Estimated Floods (m'Js) Lubok Antu 1304.7 125 29 I at Batang Ai Log-Pearson 32 542 606 662 726 770 900 1013 Pearson III Ill Meringgu at 338.2 20 24 2 Sg. Ketup Log-Pearson 60 92 !01 Ill 122 132 161 191 Gumbel Type Ill Serian at 950.5 124 21 3 Batang Sadong 23 361 437 510 607 680 923 1172 Pearson III Gumbel Type I Tuba at Sg. 28.5 3 24 Log-Pearson 4 Sebuyau 38 9 !0 12 l3 14 17 21 Gumbel Type Ill Git atSg. 425 33 13 5 Sarawak Kiri 40 640 805 964 1170 1320 1831 2346 Gumbel Type Pearson Ill - -

VI """ CHAPTERS DISCUSSION

In Sabah, the maximum, minimum and mean discharge plotted for year 1960 - 1965, 1982- 1984 and 1995- 1997 were relatively high. This is due to the great flood that occurred in early 1960's, in the middle of 1980's and Greg Storm on 1996. Storm Greg resulted in a huge flood in Keningau at the northeastern part of Sabah. In Sarawak, flood occurred almost every year during December to January.

8.1 Curve Fitting of the Distributions

The best distributions are chose based on the least standard error obtained from the analysis. Curve fitting is then done on the distributions, to obtain the regression constant 2 and R . The summary of the curve fittings using logarithmic trend is presented on the table next page. The curves which the curve fittings are based on are shown in figure 8-1 to 8-17. The numbers located at the end of each station name on the graph indicates the number of flood data for each station.

55 Table 8-l· Curve fitting Using Logarithmic Functions No. District Hydro Name of Station Name of Best Fit Equation= aLn(x) + b a b R2 Refer to Stn Region Distribution Figure .,..."'

I Sg. Tawau at Kuhara Gumbel Type I y~ 14.118Ln(x)+ 17.425 14.118 17.425 0.9994

1--r- Sg. Balung at Ba!ung Pearson III y ~ 47.211Ln(x) + 39.447 47.2ll 39.449 0.9999 1--::-- Brid2:e 0 Tawau Sg. Kalabakan at Log-Pearson III y ~ 164.98Ln(x) + 886.66 164.98 886.66 0.8514 8-I Kalabakan f--:1 Sg. Kalumpang at Mostyn Gumbel Type I y ~ 408.92Ln(x) + 281.97 408.92 281.97 0.9992 Bride:e 1---s Sg. Segama at Limkabung Gumbel Type I y ~ 373.88Ln(x) + 629.87 373.88 629.87 0.9989

.6 Sg. Kuamut at Ulu Gumbel Type I y ~ 762.37Ln(x) + 1437.6 762.37 1437.6 0.9992 Kuamut 1--J"" - Sg. Kinabatangan at Paga Pearson III -- y ~ 270.16Ln(x) + 1065.5 270.16 1065.5 0.9692 t-g Sandakan Sg. Kinabatangan at Balat Pearson III y ~ 561.97Ln(x) + 1119.5 561.97 1119.5 0.9998 8-2

1----§- Sg. Milian at Tangkulap Gumbel Type I y ~ 316.94Ln(x) + 869.12 . 316.94 869.12 0.9992

'Jo Sg. Labuk at Porog Gumbel Type I y ~ 754.45Ln(x) + 1295.6 754.45 1295.6 0.9992 1----o Sg. Tungud at Basai Log-Pearson III y ~ 183.19Ln(x) + 849.12 183.19 849.12 0.9423 12 Sg. Bongan at Timbang 8-3 Kudat Batu Pearson ill y ~ 557.17Ln(x) -156.16 557.17 -156.16 0.9982 1---j) Sg. Bengkoka at Kobon Gumbel Type I y~ 336.05Ln(x) + 397.58 336.05 397.58 0.9992 14 Sg. Sapulut at Sapu!ut Gumbel Type I y ~ 384.37Ln(x) + 570.19 384.37 570.19 0.9995 t-rs Sg. Talankai at Lotong Pearson III y ~ 56.717Ln(x) + 389.57 56.717 389.57 0.9189 t---r6 Interior Sg. Mengalong at Pearson III y ~ 79.966Ln(x) + 676.13 79.966 676.13 0.8708 8-4 Sindumin 1---u Sg. Padas at Kemabung Gumbel Type I y ~ 390.9!Ln(x) + 1030.2 390.19 1030.2 0.9992

I---rs S g. Lakutan at Mesapol Pearson III y ~ 320.72Ln(x) + 23.632 320.72 26.632 0.9957

7 Sg. Padas at Tenom Pearson III y~ 1403.7Ln(x)-1086.8 1403.7 -1086.8 0.9852 Table 8-1· ~~"~--- Curve fitting Using Logarithmic Functions No. District Hydro Name of Station Name of Best Fit Equation- aLn(x) + b a b R2 Refer to ,.._ lr) Stn Region Distribution Figure

20 Sg. Pegalan at Ansip Log-Pearson III y ~ 428.59Ln(x) - 388.67 428.59 -388.67 0.9264 8-4

21 Sg. Sook at Biah Gumbel Type I y ~ 65.552Ln(x) + 136.06 65.552 136.06 0.9992

1--zr" Sg. Padas at Beaufort JPS Gumbel Type I y- 234.92Ln(x) + 802.63 234.92 802.63 0.9992

23 Interior Sg. Baiayo at Bandukan Gumbel Type I y- 23.355Ln(x) + 33.766 23.355 33.766 0.9995 8-5 l--z4 Sg. Apin- Apin at Gumbel Type I y- 36.057Ln(x) + 42.273 36.057 42.273 0.9995 Watetworks 1--zs Sg. Labau at Sinua Gumbel Type I y- I23.72Ln(x)+ 140.59 123.78 140.59 0.9995 . tz6 Sg. Kegibangan at Log-Pearson III y- 37.707Ln(x) + 559.64 37.707 559.64 0.9745 Tampias 27 Sg. Papar at Kaiduan Pearson III y- 291.86Ln(x) + 77.019 291.86 77.019 0.9968

28 Sg. Papar at Kogopon Pearson III y ~ 452.88Ln(x) + 251.87 452.88 251.87 0.9967 29 Sg. Labuk at Tampias 8-6 Gumbel Type I y ~ 621.83Ln(x) + 854.49 621.83 854.49 0.9992 30 Sg. Liwagu at Maringkan Gumbel Type I y~75.175Ln(x)+ 184.49 75.175 184.49 0.9992 31 Sg. Moyog at Penampang Gumbel Type I y ~ 73.135Ln(x) + 246.25 73.135 246.25 0.9992 32 West Coast Sg. Liwagu at Bedukan Log-Pearson III y ~ 202.31Ln(x)- 284.02 202.31 -284.02 0.9444 33 Sg. Liwagu at Kinabalu Pack Pearson III y ~ 27.56Ln(x)- 14.025 27.54 -14.025 0.9953 34 Sg. Tuaran at Malanggang Gumbel Type I y ~ 702.12Ln(x) + 688.81 702.12 688.81 0.9995 35 Sg. Tuaran at P.H No. I 8-7 Gumbel Type I y ~ 173.58Ln(x) + 312.84 173.58 312.84 0.9992 36 Sg. Kedamaian at Tamu Darat Pearson III y ~ 179.89Ln(x) + 866.86 179.89 866.86 0.9672 37 Sg Wariu at Bridge no.2 Gumbel Type I y ~ 216.48Ln(x) + 404.48 216.48 404.48 0.9992 Table 8-2: Curve Fitting Using Logarithmic Functions for Sarawak co No. District Hydro Name of Name of Best Equation - aLn(x) + b a b R2 Refer to I ! "' Stn Region Station Fit Figure Distribution I Sri Aman LubokAntu Pearson Ill y- 66.386Ln(x) + 445.44 14.118 17.425 0.9704 at Satang Ai

2 Meringgu at Gumbel Type I y- 13.299Ln(x) + 70.132 47.211 39.449 0.9992 Sg. Ketup Samarahan 3 Serian Serian at Pearson lil y-106.84Ln(x)+ 187.17 164.98 886.66 0.9999 8-8 Satang Sadong 4 Kuching Git at Sg. Gumbel Type I y- 408.92Ln(x) + 281.97 408.92 281.97 0.9992 Sarawak Kiri

5 SriAman Tuba at Sg. Gumbel Type I y- 1.5208Ln(x) + 6.8946 1.5208 6.8946 0.9992 Sebuyau --- Sg. Tawau at Kuhara [32] .;.- Sg. Balung at Balung Bridge [15) -*"- Sg. Kalabakan at Kalabakan (21] ...... ,_Sg. Kalumpang at Mostyn Bridge [37]--+- Sg. Segama at Limkabung [29]

10000

1000

.s~ •E' 100

~• 0 i5•

10

10 100 1000 10000 Return Period (Year)

Figure 8-1: The Best Distributions for River Stations in Tawau, Sabah

-+- Sg. Kuamut at Ulu Kuamut[38] ----·· Sg. Kinabatangan at Pagar[21] ...... ____ Sg. Kinabatangan at Balat[38] -*-Sg. Milian at Tangkulap[38] _....Sg. Labuk at Porog[32] --+-Sg. Tungud at Basai[38]

10000

1000

;@; .s •~ 100 jj• ••Cl

10

10 100 1000 10000 Return Period (yearl

Figure 8-2: The Best Distributions for River Stations in Sandakan, Sa bah

59 --+- Sg. Bongan at Tim bang Batu[19] _.,_ Sg. Bengkoka at Kobon[38] I

10 100 1000 10000 Return Period (Year)

Figure 8-3: The Best Distributions for River Stations in Kudat, Sabah

--+- Sg. Sapulut at Sapulut[17] -11- Sg. Talankal at Lotong[14) -·•- Sg. Mengalong at Sindumin[23] -"*"""" Sg. Padas at Kemabung[38] """"*""- Sg. Lakutan at Mesapol[21] --+- Sg. Padas at Tenom[17] ---+--- Sg. Pegalan at Ansip[38]

100

10

10 100 1000 10000 Return Period (year)

Figure 8-4: The Best Distributions for River Stations in Interior (I), Sabah

60 -+-Sg. Padas at Beaufort JPS[16] -•- Sg. BaiaYo at Bandukan[14] --4-- Sg. Apin- Apin at Waterworks[11] --*""- Sg. LabaU at Sinua[14] ...... - Sg. Kegibangan at Tampias[l OJ ~Sg. S~o:k_oa,._tB~i:"'ah"l[C':38"!] ____j I

10000

1000

"gM •~ 100 ~•u 3

10

10 100 1000 10000 Return Period (year)

Figure 8-5: The Best Distributions for River Stations in Interior (2), Sabah

-+-- Sg. Papar at Kaiduan[37] -a-Sg. Papar at Kogopon[37] -•- Sg. Labuk at Tampias[24]

10 100 1000 10000 Return Period (Year) Figure 8-6: The Best Distributions for River Stations in West Coast (1), Sabah

61 --+-Sg. Tuaran at Malanggang[14] -+-Sg. Tuaran at P.H No.1[20] ...... -sg. Kedamaian at Tamu Darat[38] -)(-Sg Wariu at Bridge no.2[38] --sg.liwagu at Kinabalu Park[14]

10 100 1000 10000 Return Period (Year) Figure 8-7: The Best Distributions for River Stations in West Coast (2), Sabah

--e- Lubok Antu at Satang Ai [29] _..,_ Meringgu at Sg. Ketup[24] --x- Serian at Batang.Sadong[42] --.-Git at Sg. Sarawak Kiri[13] -+-Tuba at Sg.Sebuyau[24]

1000

~ g • ~ 100 <• ~ i5

10

10 100 1000 10000 Return Period (Year)

Figure 8-8: The Best Distribution for River Stations in Sarawak

62 8.2 Best Distributions

There are 64 rivers in Sabah 44 gauging stations in Sabah. Among all of the data received only 37 had been analyzed. For Sarawak the total numbers of water level gauging stations are 79 and only 5 stations had been analyzed due to some difficulties (Refer to Appendix B).Based on Flood Frequency Analysis, the two distributions with the least standard error are taken as best-fit distribution for the station analysed.

Best-fit distribution specifies the distribution for each station with least amount of standard error. Two best fit-distributions show the two distributions with minimum standard error. As an example, for station of Sg. Tawau at Kuhara, Tawau (refer Appendix B), the two best-fit distributions are Gumbel Type I and Log-Pearson III. The Gumbel Type I method has the least standard error of 2.45 and Log-Pearson III has the second least standard error of 2.87.

In short, the most common distributions analysed with least error are Gumbel Type I, Pearson III and Log-Pearson III. Other distributions such as Log-Normal 2, Log, Normal 3 and Weibull Plotting Position have large error thus will not be included in the analysis.

From the analysis done Predicted Discharge of Various Return Periods graph are plotted. Log-Normal 3 distributions have the highest discharge for a specified return period, while Log-Pearson III and Pearson III yield the least discharge. Thus, the selection for the best distribution for analysis is very important as it will decide the cost of the structure design, construction and drainage system.

63 8.2.1 Whole of Sa bah

BEST TWO-FIT DISTRIBUTION FOR WHOLE SABAH

~Gumbel Type I 20% 0 Log Pearson Ill 0 Pearson Ill 0 Log Normal 2

32%

Figure 8-9: The First Two Best-Fit Distributions for the whole Sabah

From the pie chart above, the first best two-fit distribution are Gumbel Type I (34 %) and Log- Pearson III (32%) followed by Pearson lii (20%) and Log- Normal II (14 %). When it is said that 40 percent of the first two distributions are Gumbel Type I, it means that Gumbel Type I distributions is one of the two distributions with least standard error for 34 percent from the total 74 analyse. Thus, this shows that Gumbel Type I is generally the best distribution to be used for Sabah followed by Pearson III, Log-Pearson Ill and Log Normal 2.

64 8.2.2 Tawau

Tawau is situated on the South-East Coast of Sabah. It is facing the interior mountain ranges on the west and the Celebes Sea on the east. Overall Tawau has 11 rivers and 8 river gauging stations. Tawau receives about 2000-2500 mm rainfall annually.

For Tawau, there are 5 stations had been analysed. The two best-fit distributions are Log Pearson Ill (40%), Gumbel Type I (40 %), Pearson III (10%) and Log-Normal 2 (10 %). Most of the stations have a mean flood less than 50m3/s except for station in Sg. Segama at Limkabung. Sg. Segama is located in Lahad Datu area 110 km from Tawau town.

BEST TWO-FIT DISTRIBUTION FOR TAWAU DISTRICT

~Gumbel Type I 0 --~Pearson Ill DLog-Pearson Ill 0 Log-Normal 2 40%

10%

Figure 8-10: The First Two Best Fit Distribution for Tawau District

The best distribution to be used in Tawau District is Gumbel Type I or Log-Pearson 111, followed by Pearson 1Il and Log-Normal2

65 8.2.3 Sandakan

Sandakan is situated on the East coast of Sabah. The longest river in Sabah is located in Kinabatangan, Sandakan Sabah. There are 14 river gauging stations in Sandakan. Sandakan receives 3000-3500 mm annual rainfall in the interior Kinabatangan and Tangkulap area and 2000-2500 mm at the coastal area. There are 5 stations had been analysed in Sandakan. The two best-fit distributions are Gumbel Type I (33%), Log­ Pearson Ill (25 %), Pearson III (25%) and Log-Normal 2 (17 %). Most of the rivers in Sandakan has a big mean flow which is more than 100m3/s especially Sungai Kinabatangan which has total mean flow of 406m 3/s.

BEST TWO-FIT DISTRIBUTION FOR SANDAKAN

l2l Gumbel Type l 0 Log Pearson 1! 1 DPearson Ill 13 Log Normal 2 25%

25%

Figure 8-11: The First Two Best Fit Distribution for Sandakan District

The best distributions to be used in Sandakan are Gumbel Type I, followed by Pearson 1II, Log-Pearson III and Log-Normal 2 I

66 8.2.4 Kudat

Kudat is situated in the northernmost part of Sabah. On the west, it faces the South China Sea and on the east the Sulu Sea. It serves as the division administrative centre for the , which includes Kudat, Pitas, Kota Marudu and some islands. There are only 4 river gauging stations in Kudat area.

Kudat receives about 2000-2500 mm of rainfall annually. For Kudat, The two best-fit distributions are Gumbel Type I (40%), Log-Pearson III (20 %), Pearson III (20%) and Log-Normal 2 (20 %). Most of the rivers in Sandakan have a mean flow of less than 50m 3/s which shows that the river flows is quite low.

BEST TWO-FIT DISTRIBUTION FOR KUDAT

G!l Gumbel Type I DLog Pearson Ill DPearson Ill 0 Log Normal 2

20%

Figure 8-12: The First Two Best Fit Distribution for Kudat District

The best distributions to be used in Kudat are Gumbel Type 1, followed by Pearson Ill, Log-Pearson lJI and Log-Normal 2

67 8.2.5 West Coast

The west coast of Sabah has the largest number of stations covered compared to other districts. There are 23 river gauging stations in West Coast areas. Most of the places with high population such as villages and towns located along the rivers in West Coast.

The two best-fit distributions are Pearson III (32%), Gumbel Type I (27%), Log-Pearson Ill (23 %), and Log-Normal 2 (18 %).

BEST TWO-FIT DISTRIBUTION FOR WEST COAST

!l Gumbel Type I D Log Pearson Ill OPearson Ill D Log Normal 2

32%

23%

Figure 8-13: The First Two Best Fit Distribution for West Coast District

The best distributions to be used in West Coast are Pearson III, followed by Gumbel Type I, Log-Pearson III and Log-Normal 2

68 8.2.6 Interior

For Interior District, Gumbel Type I is the best distributions for 31 percent of the total of 26 analyse, followed by Log-Pearson III 27 percent, Pearson III 27 percent and log­ Normal 2. Most places in Interior Sabah consider the driest place in Sabah but there are some places in the district such as Tenom located in the flood plain.

BEST TWO-FIT DISTRIBUTION FOR INTERIOR

[;il Gumbel Type I D Log Pearson Ill 0 Pearson Ill 0 Log Normal 2 27%

27%

Figure 8-14: The First Two Best Fit Distribution for Interior District

Generally, the best distributions to be used in Interior are Gumbel Type I, followed by Log-Pearson III, Pearson III and Log-Normal 2.

69 8.2.7 Sarawak

As the total number of stations analyzed for Sarawak is 5 only, it is not right to conclude the best-two fit distribution for the state. The best-two fit distributions stated below are based on 5 stations that had been analysed. All of the stations located at the south .of Sarawak. Base on the analysis, it is still true that Gumbel Type I and Log-Pearson III are the best distributions to be used.

BEST TWO-FIT DISTRIBUTION IN SARAWAK (VALID FOR 5 STATION ONLY]

40% ta Gumbel Type l

D Pearson Ill

0 Log-Pearson Ill

20%

Figure 8-15: The First Two Best Fit Distribution for Sarawak (valid for 5 stations only)

70 8.3 Correlation between Catchment Area and Average Discharge

Theoretically, the average discharge of a river is largely dependent on its catchment area hence the larger the catchment area, the higher the average discharge of the river. This is true as the increasing in area will result to a higher volume of precipitation (height x area).

In this project for the river analysis, the relationship between the average discharge and its catchment area is determined using a graph of total mean versus its catchment area. The first graph plotted is the graph of total mean versus the catchment area of the whole rivers analysed (Figure 8-16). The best fit line does not consider the points outside the range of average data. Based on the graph, the total means increases with the catchment area. This is true for most of the rivers in Sabah and Sarawak.

450.

2 R = 0.7279 400 ---.------

350

300 !';; E. 250 -- < • • • ~ 200 ------•------" ------···- --• ~ • >- • 150 • • • 100 ------·----- • 50 • • • 0 0 2000 4000 6000 8000 10000 12000 Catchment Area(km2)

Figure 8-16: Total Mean Discharge versus Catchment Area for Sabah and Sarawak

71 In the figure 8- I 7 below, shows the total mean discharge versus catchment area for areas 2 less than I 000 km , while Figure 8- I 8 shows the total mean discharge versus catchment 2 area for areas larger than 1000 km , for Sabah and Sarawak. Both graphs illustrate that as the catchment area increases, the total mean discharge also increase

60 •

50 • • 40 ------• • •

20 ------·---- • --···---.------

•

0 100 200 300 400 500 600 700 800 900 1000 Catchment Area (km2) Figure 8-17: Total Mean Discharge versus Catchment Area for Sabah and Sarawak

450

2 R "' 0.6849 400

350 ------.....

300 ~ .s 250 ~ ~ 200 • • ~ • 150 ------• • 100 ------• • • 50 ------·---

o+----~----~---~----~---~---- 0 2000 4000 6000 8000 10000 12000 Catchment Area Figure 8-18: Total Mean Discharge versus Catchment Area for Sabah and Sarawak (More than I 000 km 2l

72 CHAPTER9

CONCLUSION AND RECOMMENDATION

9.1 Conclusion

A practical flood frequency analysis for Sabah and Sarawak has been presented. Streamflow data had been collected for Sabah from 1965 - 2006 and Sarawak 1965- 2005. The streamflow are mainly obtained from Hydrology and Survey Department, Department of Drainage and Irrigation in Sabah and Sarawak. Most of the data obtained in form of softcopy. The total numbers of stations analysed are 37 out of 44 total numbers of river gauging stations in Sabah and 5 out of 79 stations in Sarawak. The data were put into database and frequency analysis of the data is done using software.

From the result obtained, it can be concluded that in general the best distributions to be used for frequency analysis in Sabah are Gumbel Type I and Log-Pearson Ill. The result is in conforming to the recommendation by Department of Irrigation and Drainage (DID) Malaysia for flood prediction in manual provided (H.P 4) which uses Gumbel Type I. For Sarawak, the best distributions for 5 stations analysed are Gumbel Type I and Log­ Pearson III.

73 9.2 Recommendation

Investigation is needed in order to identify the development and changes in water intake at each river analyse. A river diversion project may cause the streamflow to reduce significantly after a specified year. Besides, any urbanization process occurs at the upstream may disturbed the streamflow in other words urbanization may reduce the permeable layer of soil and increases the streamflow. Thus a detail investigation should be made to ensure the data used for prediction of flood is accurate and reliable.

For a more comprehensive result, the river stations 111 Sabah should be increased. However, as the river gauging stations is specified by the Department of Irrigation and Drainage Malaysia and the number is fixed, it is very difficult to obtain more stations for analysis.

The analysis of river stations in Sarawak should be continued to be conducted. An extra task and initiative should be made to any person doing the research as DID, Sarawak do not have any reliable source of determining flood discharge for all of the rivers in the state. According to Yeo Howe Lim (2003) in his paper it difficult to estimate flood in mostly place in Sarawak as the states facing problems such as many rivers remain ungauged, shortness of records and inaccuracy of flow rating curves. There should be more rating curve for rivers.

In Sabah and Sarawak both states are not using Hydrology region as use in the Peninsular Malaysia thus, it is difficult to. see the relationship between the distributions and the regions. A specific rainfall study should be made in Sabah order to relate rainfall magnitude and flood in Sabah.

74 REFERENCES

1. Kite, G. W., 1988, Frequency and Risk Analyses in Hydrology, Water Resources Publications 2. Subramanya, K., 2003, Second Edition, Engineering Hydrology, Tata McGraw­ Hill Publishing Company Limited 3. McCuen, Richard H., 2005, Third Edition, Hydrologic Analysis and Design, Pearson Prentice Hall 4. Krishnan, R., Daria Mathew A. and Koay, L., 2001, The Influence of Highland and Forests, Wetlands on Floods in Malaysia, World Wide Fund for Nature (WWF), Selangor 5. Balamurugan, G. and Mohd. Razali M. R., 1999, The Implications of Land Use Change on the Hydrology of Sungai Kinabatangan, Paper presented at Seminar on Mill Effluent and Pollution Management, WWF-DOE, Sandakan, 28 · 29 April 1999 6. Gassim M. M., Mazlan Abd. Ghaffar, Sanudin Tahir and Arbain Kadri, 1994, Flood Hazards of Kola Kinabalu, Sabah, ENSEARCH International Conference Proceeding, 19 · 21 October 1994, Shangri- La Hotel, Kuala Lumpur, P. 575 • 584 7. Lim, Y. H. and Lye, L. M., 2003, Regional Flood Estimation for Ungauged Basins in Sarawak, Malaysia, Hydrological Sciences Journal 48( I), 79 · 94, February 2003 8. Jabatan Pengairan dan Saliran Malaysia, 2001, Mean Monthly, Mean Seasonal and Mean Annual Rainfall Maps Sabah and Sarawak for Jabatan Pengairan dan Saliran Malaysia 9. Ministry of Agriculture and Fisheries , Sabah, 1965, Hydrological Records of Sabah to 1968, Hydrology Division of the Drainage and Irrigation department, under supervision of Mr. 1 Rozdal, Colombo Plan Expert in Hydrometric Survey 10. Ministry of Agriculture and Fisheries , Sabah, 1980, Hydrological Records of Sabah to 1969-1975, Drainage and Irrigation and Department, Sabah

75 II. Ministry of Agriculture Malaysia, 1985, Hydrological Data- Streamflow Records 1975-1980, Sahagian Pengairan dan Sal iran, Kementerian Pertanian Malaysia 12. Ministry of Agriculture Malaysia, 1988, Hydrological Data- Streamflow Records 1980-1985, Sahagian Pengairan dan Saliran, Kementerian Pertanian Malaysia 13. Ministry of Agriculture Malaysia, 1995, Hydrological Data- Streamflow Records 1985-1990, Sahagian Pengairan dan Sal iran, Kementerian Pertanian Malaysia 14. Philip B. Bedient and Wayne C. Huber, 2002, Hydrology and Floodplain Analysis, Prentice Hall 15. Nabilah Abu Bakar, 2005, Frequency Analysis of Riverjlow in Malaysia, Universiti Teknologi Petronas 16. Saiedi S., 1989, 'DISTRIB', Hydrological Frequency Analysis for Flood Forecasting, Water Resources Consulting Engineers, Tehran, Iran

'76 APPENDICES

77 APPENDIX A CORRESPONDENCE ON DATA COLLECTION

78 UNIVERSITI TIKNOLOGf PETRONAS

Saied Saiedi, Assoc. Prof., Ph.D., Civil Engng., Dept., University Technology PETRONAS (UTP) 31750Tronoh, Perak, MALAYSIA Ph.+ 605 368 7284 Fax: +605 365 6716 E-mail: [email protected] )irector, Attention: Assistant Director .Vong Wen Ho), )rainage and Irrigation Department Sarawak, :zdrology and Water Resources, I and lOth Floors, .visma Saberkas, lln Tun Abg Haji Openg, P.O Box 1230, >3626, Kuching, Sarawak 27 April 2007

['el: +6082-421506 Fax: +6082-426400

)ear Sir,

• have a final year student, Mr. A wang Azfar b. Awang Ali Bahar, working on his final year thesis 'Frequency Analysis offloods in Sabah and Sarawak". My student and I have had correspondence and risits with your counterpart Mr. Thomas Lau and other colleagues of your department such as Mrs. 'Iidayati, and Mr. Lo Hong Min who have kindly assisted by providing some data for some river ;tations (water level data for 17 stations) and the rating curves of some (28) stations in Sarawak.

Yfy student is at the final stage of his research and he requires some supplementary data that include: I • Updated rating curves of the stations. I remember Mr. Lo was working on them early last year.

• Flood data (water level or discharge) of the river stations up to 2006.

~c. Mrs Hidayati Tel:082 662135, Fax: 082 662019 . :rv1r Lo Hong Min " " " "" " " "" " " "" " " "" " " "

79 UNl' ERSlTI TEK~i'WGI PETJ·J)NAS

Saied Saicdi, Assoc. Prof., Ph.D., Civil Engng., Dept., University Technology PETRONAS (UTP) 317 50 Tronoh, Perak, MALA YSV\ Ph.+ 605 368 7284 Fax: +605 365 6716

E-mail: saiedsaiedi @petronas.com.my

Mr. Ho Tsun Lin Hydrology and Water Resources Department of hrigation and Drainage, Level 5, Wisma Pertanian, Jalan Tasik Luyang, Off Jalan Maktab Gaya, Locked Bag 2052, 88767 Kota Kinabalu, Sabab

Tel: +60 88-430689 Fax: +60 88-432780

2nd March 200

Dear Sir,

Mr A wang Azfar B A wang Ali Bahar is a final year civil engineering student at UTP workin.' on his Final Project on "Frequency Analysis of rainfall and runoff in Sabah and Sarawak under my supervision. The Final Year Project Course covers two semesters and he is at th beginning of the first semester. I would appreciate if you could instruct your colleagues V assist us in obtaining the following information needed for our research.

1) "Streamflow Records" from the earliest years available until late 2005, both softcopy an hard copy.

2) The list of all related publications by DID Sabah.

Sincere~y,Assoc. Prof. or. Salad Saledl ecturer Civil Engineering Programme Saied Saie Unlversitl Teknologl PETRONAS . 31751) Tronoh Perak Darul Ridzuan, MALAYSIA.

Ps. this is the second correspondence for the same request. The first was directed to the Assistant Director on 28 Feb. Later, my student told me that a new letter is to be directed to Mr. Ho Tsun Lin.

80 • • JABATAN PENGAIRAN DAN SALIRAN Bahagian Hidrologi dan Ukur Lorong Burung Keleto Telefon : 088-430689 89350, Inanam, Kota Kinabalu No. Faks: 088-432780 Sabah, Malaysia Email : jpsssil @tm.net.my

RUJ KAMI: JPS(H&U)/1/2/4/5 Pt.3(19)

TARlKH 20 Mac 2006

Encik Awang Azfar B. Awang Ali Bahar Village 5A, L-4-3-2 University Technology PETRONAS (u'rr) 31 7 50 Tronoh PERAK

Tuan

Permohonan Data Hidrologi

Dengan segala hormatnya, borang permohonan data tuan bertarikh 08 Mac 2006 dan sural sokongan daripada Assoc. Prof. Dr. Saied Saiedi diterima pada 13 Februari 2006 dan 06 Mac 2006 masing-masing mengenai dengan perkara di alas adalah dirujuk.

2. Bersama-sama ini dibekalkan data luah purata harian bagi stesen-stesen sungai seperti yang disenaraikan dalam Lampiran melalui erne! untuk tindakan tuan selanjutnya.

3. Tiada sebarang bahagian data berkenaan dibenarkan untuk disalin atau dicetakkan untuk tujuan lain dan haruslah diguna semata-mata untuk projek yang dimaksudkan alas budibicara sendiri.

Sekian, harap maklum.

"BERKHIDMAT UNTUK NEGARA DENGAN BERSIH, CEKAP DAN AMANAH" • Saya yang menurut perintah

Penolong Pengarah Kanan Bahagian Hidrologi Dan Ukur b.p. Pengarah Pengairan Dan Salirari Negeri Sabah KOTA KINABALU

s.k. Assoc. Prof. Dr. Saied Saiedi Lecturer Civil Engineering Department University Technology PETRONAS (UTP) 31750 Tronoh · 81 PERAK

'BERJIMAT DAN MENABUNG AMALAN MULIA' 'JAYAKAN PERKHIDMATAN SEMPURNA'

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From: "Dos Saguman" View Contact Details r:;.:1

To: "Saied Saiedi (UTP)" , "Awang Azfar"

CC: "Ho Tsun Lin"

Subject: ,¢/' Flow Data - Min and Max Instantaneous Value.

Date: Thu, 3 May 2007 15:12:01 +0800 iaied Saiedi, Assoc Prof Dr :ivil Engineering Dept, University Technology PETRONAS (UTP) >1750 Tronoh, Perak, Malaysia lear Sir

1s directed, i am sending you the above mentioned data for your attention.

'lease do not hesitate to enquire if in case you have any question regarding this matter.

·hank you

'ours Sincerely los Saguman Jnit Prosesan Data Hidrologi !ahagian Hidrologi dan Ukur PS lnanam. Plain Text Attachment [ Scan and Save to Computer]

~~ NIWA Tideda ~~~ JPS Sabah 3-MAY-2007 3:29

6/12/2007 10: - awgazfar_ [email protected] tlle:///G:/ShowLeit

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"his message is not flagged. [ Flag Message ~ Mark as Unread ] Printable V1ew ubject: data clarification for Sabah rivers

'ate: Fri, 27 Apr 2007 18:39:45 +0800 rom: "Saied Saledl (UTPY []View Contact Deta11s o: [email protected]

C: [email protected], [email protected], [email protected] o: Senior Assistant Director Ho Tsun Lin, Hydrology and Survey Section, Department of Irrigation and Drainage, Lorong Burung Keleto, 89350, lnanam, Kola Kinabalu, Sabah

el: 088-280520 Fax: 088-432780

ear Sir,

eferring to the flood data that are already provided by your colleagues for the research work of my student nr. Awang Azfar b. Awang Ali Bahar), I would like to ask for a clarification:

the book entitled "Hydrological records for Sabah, 1969-1975" (as an example) the discharges are totally fferent from the data given by your good colleague Mrs Chin Lee Yun through correspondence in the past. Jr example, for "site 4959401 SG. PADAS at KEMABONG" in 1971, the maximum flood is 2199.6 while in the >flcopy it is 739.3. The difference is usually huge. Other river stations and other years have the same ·oblem. It may well be because of different rating curves used or ....

;; we are at the end of the data analysis and we should decide about which one to choose, I would like to ask >u to kindly tell your colleagues to give some explanation to be considered before finalizing the choice of 1e data.

Truly yours, Saied Saiedi, Assoc Prof Dr Civil Engineering Dept, University Technology PETRONAS (UTP) 31750 Tronoh, Perak , Malaysia Tel: 05-368 7284, Fax: 05-365 6716

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6/12/2007 10: Appendix A: Correspondence from DID, Sarawak

A.l Introduction

On 4' 11 May 2007, the author had faxed a letter to Mr. Wong Wen Ho, Assistant Director of Hydrology and Survey Department (082-424400) also sending copy to Mrs. Hidayati, Engineer and Mr. Lo Hong Min to request new water level data and new rating curves. The following memo will explain the situation after had a phone conversation with the authority.

A.2 Water Level Data

All of data provided and received by Drainage and Irrigation Department, (DID) Sarawak were in term of water level. As this study is using discharge the author has to convert the water level into discharge to ease the analysis. Thus, in order to convert them, the author have to make some calculation based on rating curves given by the DID.

On last year, we received rating curves formula based on Sarawak Hydrological Year Book 2001. There were 29 rating curves for 29 stations out of 79 stations in Sarawak. The rating curves provided had an effective range. Most of the flood and big flow condition were out of the range. Any calculations more than effective range are not valid in term of discharge.

A.2 Explanation from the authority

On 10 111 May 2007, the author had a phone conversation with Mrs. Hidayati, Engineer (082-662135) in Hydrology and Survey Department for further explanation and enquiry. In the phone conversation, the author raise some question about nature of data provide by DID Sarawak were different from other states. In the previous project done by Miss Nabila, and data obtained from DID, Sabah for this project, all of the data received from

85 each DID states were in term of discharge. Mrs. Hidayati explained that the author should not doubt on the nature of data they have. The data they had provided had been used for a very long time and established. Any further process such as discharge conversion should be made by any person himself for his own use.

Besides, in her further explanation for flood condition the rating curves should not be used as the water level is out of effective range. They will not provide any rating curves for bigger range. The person or any researcher himself should produce his own rating curves in order for them to obtain the discharge. In addition, they had provided such enough data for any researcher .Furthermore, she explained that it is hard for them to obtain rating curves for other river as her department has a few employees only and should not be blame for their handicapped. In this phone conversation as well she added that there were no new rating curves available. Any calculation should base on Rating Curves Formula published in Sarawak Hydrological Year Book 2001 (the latest that available).

A.4 Discharge reading in Hydrological Data (1975-1990)

In the publication Hydrological Data, River Discharge and Suspended Sediment Records ( 1975-1990) published by DID, Malaysia, there were 14 Sarawak stations in the book and the reading were in discharge. As I have some water level data in softcopy I had calculate them into discharge and compare them with the publication. The readings were totally different. Regarding this I called Mr. Kevin, Engineer (082-662135) in the Hydrology and Survey Department to explain more about the condition. In the phone conversation Mr. Kevin makes clear that I should not compare the value in the book Rnd compare them with the recent calculation. The value in the book only valid during the time their gauge it and obviously they have different effective range and rating curves formula on that time.

86 SUNGAI TAWAU ATKUHARA, TAWAU, SABAH

STATION NUMBEB' 411!401 Not~ : In. 31 ped·:.dsr J:"'U ~ 0 ~ va.l:u.e(:s:) RID 1 8ero(:s:)

furr.of :;:, 845 .49 furr.of Lli!IX)= 96.08 fu:21n. of X= 21.21 lklm of Lli!IX)= 3.20 St:m&rd Dev. of :;:, '15.61 Stzm.&:t-3. Dev. of Lli!IX)= 0.54 Skew Coef. of :;:, 0.?1 Sk~ Cooef. of Lli!IX)= -0.01 \Tzu:Ution Coef. of X:: 0.5? Vm:iation Coef. of LN(X)::: 0.11

retum. pez:iod (j:~a.t:) 2 5 10 20 25 50 15 100 200 500 1000 10000 :s:tMI.d.M:d eno ======:::======:::::;;;;:;:;::;;;;;::;;;::::::::::::::::::::::::::======:::::::::::::::::::::::::::::::::::::::::::::::::;::;::;:;;:;:;::;::;;:;::::::::::::::::::::::::::::::::::::::;::;:;:;:::::::::::::::::::::::::::::::::::;:;;:;::::::::::::::::::::::::::;:::::::::::::::::::::::::::::::::::::::::::;:;::;::;:;:;::::::::::::: 2?.21 40.12 41.06 52.11 54.39 59.19 61.71 63.43 61.36 12.11 15.41 85.30 4.03

-LOG - NORl!iU. 2 pM: . ( H ) 23.65 36.11 46.48 56.49 59.69 10.35 76.10 81.33 93.08 109.51 122.63 112.12 3.34

LOG- I!OP.lmL 2 >"""· I L) ' 24.60 38.31 48.56 59.01 62.43 13.62 80.28 85.14 9?.4? 114.?1 128.49 180.43 26.14

GtltillEL !TI>< I I H l 24.93 40.18 50.51 60.43 63.48 73.26 1'8.84 82.19 92.45 105.12 ll4.63 146.52 2.45

GtltillEL !TI>< I I L ) 24.69 38.40 4'7 .69 56.60 59.35 68.14 ?3.15 'i'6.1l 85.38 96.1? 105 .32 D3.99 2.78

LOG - Pm.RSON III I H) ' 24.63 38.32 48.52 58.96 62.28 13.34 19.92 84.?1 96.84 ill.15 12?.22 11?.16 2.8?

LOG- I!OP.lmL 3 >"""· I H) ' 22.9? 29.44 36.90 41.18 51.02 66.14 ?6.?6 85.32 ll0.28 J53.D 194.38 411.02 8.89

LOG - I!OP.lmL 3 P""· I L ) ' 24.'15 38.31 49,38 61.09 64.90 11.19 85.59 91.35 106.16 12? .32 144.54 211.?0 2.92

Pm.RSON III I H) ' 25.46 39.25 41.11 55.42 5?.69 64.10 68.56 ?1.25 11.64 85.?5 91.65 ll0.68 3.00

Pm.RSON III I L) 24.10 38.66 49.21 59.5? 62.18 13.D 19.06 83.29 93.63 101.30 111.63 '152 .18 2.60

PLOTITIIll POSITION FOillllJLA 23.68 41.61 53.66 60.68 61.54

( H ) : Hom:nt:s: Hethod ( L ) : &x:inum. L:ikelihood lk:thod

c-: APPENDIXC DETAIL OF RIVER STATIONS ANALYSED

88 SABAH

89 SUNGAI PADAS AT KEMABONG

Description by DID, SABAH Summary of Data

Station No. 4959401 Sungai Pad as at SUNGAI PADAS AT KEMABONG Name Kemabong 2 Area (km ): 3185

Gauging site:~ 130m cableway Elevation (m): 183

Longitude & Latitude:~ 115"55' 15" E 04 '55'00" N. Average Rainfall (mm) Catchment Area:- 3185km2 Water Use 3 Elevation above mean sea level:-183 m Total Mean yearly (m /s): 113.77 3 Catchment characteristics:- Mean of"Min"s yearly (m /s) 13 3 (f) Shape:- The maximum length and breadth of the Mean of"Max"s yearly (m /s): 1296.53 3 catchment are 90 km and 55 km respectively Absolute Min, yearly (m /s): 2.74 3 (g) Topography:- Mountainous with elevation up to 2000m Absolute Max yearly (m /s): 2404.2 (h) Vegetation :- Virgin and secondary jungle with some Hydrological Records for Sabah, 1968-1975, DID shifting cultivation Sabah (i) Soil Cover:- Sandy loams 204m deep Source (J) Rod: Type East side of catchment: sandstone, Streamflow and River mudstone. West side of catchment: siltstone shale, Suspended Sediment Records, 1975-1990, DID, massive sandstone Malaysia Ranged of obse•·vations:- The range of river stages observed is from l8.93m to 26.42m

90 --+--Annual Average -Annual Flood · · · ···Annual Drought

3000

2500

"'-M 2000 .s., 2' 1500 J: "() 1000 i5"' 500

0 ,"""",-'-,-.... ,-_ ...... ,~ ...... '--'-,'--'-- .__.__.__,_ '---'..-- ....:..,-..... , ...... _,_ ...... '--'-- '--'- -'--,'-- ...... ,--'-.-=- .__,_ --- ._._ ...... __,_ '-'- '--'--,"--'-,'--'-

Year

Figure C-1: Annual Discharge of Sg. Pad as at Kemabong (1969-2006)

--..-Plotting Position (Weibull) -•-· Pearson !II Log-Normal 3 Log-Pearson HI -+-Gumbel Type I -e-- Log-Normal2 100000

10000

~ 1000 Mg • .c• "u 6 100

10

10 100 1000 10000 Return Period (Year) Figure C-2: Frequency Analysis of Annual Floods in Sg Padas at Kemabong (1969-2006)

91 SUNGAI KUAMUT AT ULU KUAMUT Location

Description by DID, SABAH Summary of Data

Station No. 5074401 Sg. Kuamut at Ulu SUNG AI KUAMUT AT ULU KUAMUT Name Kuamut Area (km'): 2950 Gauging site:- Gauging by boat Elevation (m): 30 Longitude & Lfltitude: - I I 7"26'30" E 05'04'55" N. Averaoe Rainfall (mm) Catchment Area:- 2950 km 2 Water Use 3 Elevation above mean sea level:- 30m Total Mean yearly (m /s): 122.66 3 Catchment characteristics:- Mean of"Min"s yearly (m /s) 8.2 3 (a) Shape:- The maximum length and breadth of the Mean of"Max"s yearly (m /s): 1956.92 3 catchment are 90 km and 50 km respectively Absolute Min, yearly (m /s): 2.31 3 (b) Topognlphy:- Hills and mountainous with elevation up Absolute Max yearly (m /s): 4121.3 Hydrological Records for to 1500m Sabah, 1968-1975, DID (c) Vegetation :-Virgin jungle Sabah (d) Soil Cover:- Sandy to clayey soils of 1-3m deep Source (c) Rock Type: - Sandstone, mudstone and some chert and Streamflow and River basalt in upper catchment. Suspended Sediment Records, 1975-1990, DID, Malaysia

Ranged of observations: - The range of river stages observed is from 12.45m to 28.99m. Discharge measurements have been taken between 12.44 and 18.63 m

92 I-+- Annual Mean -a-Annual Flood Annual Drought I

4500.00

4000.00 -~---~--~--~n 3500.00 ~ 3000.00 .§.. Q) 2500.00 "'~ 2000.00 .c"' 1/) 1500.00 i5" 1000.00 500.00 111J ~ ,_ A_t_ft ._._4\ . I t t I II ft t • I (I; I (I) ...... I A ft t.-+ 0.00 -- -.- --- .---. mmmmmmmwwmmmmmmmmwmmmmmmmmmmmwmwoooooooo mm~~~~~~~~~~~~~~oooooooooooommmmmmwmmmoooooooo------~-NNNNNNNN oowo~Nw~~m~oowo~Nw~~m~oomo~Nw~~m~oomo~Nw~~m~ Year

Figure C-3: Annual Discharge at Sungai Kuamut at Ulu Kuamut

-+-Plotting Position (Welbull) -tt- Pearson Ill Log-Normal 3

100000

10000

1000

100

10

10 100 1000 10000 Return Period (Year) Figure C-4: Frequency Analysis of Annual Floods of Sungai Kuamut at Ulu Kuamut, (1969-2006)

93 SUNGAI PADAS AT TENOM Location

Description by DID, SABAH Summary of Data

Station No. 5159401 Name I Sg. Padas at Tenom SUNG AI PAD AS AT TEN OM 2 Area (km ): 7718 Elevation (m): 168 Gauging site:- Gauging by boat Average Rainfall (mm) Longitude & Latitude: -115"55'50" E 05'07'00" N. Water Use I 2 Catchment Arca:-7718 km Total Mean yearly (m3/s): 182.33 Elevation above mean sea level:- 168m Mean of"Min"s yearly (m3/s) 25.63 Catchment characteristics:- Mean of"Max"s yearly (m 3/s): 1633.2 3 (a) Shape:- The maximum length and breadth of the Absolute Min, yearly (m /s): 4.95 3 catchment are 60 km and 200 km respectively Absolute Max yearly (m /s): 4730.1 (b) Topography: - 20% ALLUVIAL with elevation Hydrological Records for 200-600m. 60% hills (IOOOm) and 20% mountains with Sabah, 1968-1975, DID Sa bah elevation up to 2600m. Source (c) Vegetation :- Padi and various other crops, grassland Streamflow and River rubber trees, v1rgin and secondary jungle Suspended Sediment (d) Soil Cover: - Sandy loams 204m deep. Mountains· Records, 1975-1990, DID, Sandy loam of 1-2m deep. Alluvium: Various textures in Malaysia layers of I 0-20 m deep_ Fine to coarse sand, loam of 2-5 m deep (e) Rocli Type: - East side of catchment: Sandstone, mudstone West side of catchment: Siltstone shale, massive sand stone. Sandstone and mudstone predominant '" upper catchment: South side of catchment: Sandstone, mudstone. North side of catchment: Alluvial gravel Ranged of observations:- The range of river stages observed is from 19.6 m to 27.64m

94 ---+-Annual Average ---Annual Flood Annual Drought

5000.00 4500.00 4000.00 ~ 3500.00 M .s 3000.00 ~..... 2500.00 ~ 2000.00

5 ~~~~.~~ -~~=~-=-~·--- 50~~~ +--~~.-----:~·· ~--:-~

~~ ~~~~~~ ~~~~~~ wwwwwwww~ww~~~~~wwwwwwmwww mmm~~~~~~~~~ ~~~~oooooooooooo~w~w ~oowo~~w~~m~oowo~Nw~~m~oowo~N Year

Figure C-5: Annual Discharge of Sg. Padas at Ten om (1969-2006)

...... _..Plotting Positior, ...... ·Pearson Ill log-Normal 3

Log-Pearson Ill --+-Gumbel Type I -+-Log-Normal 2 I

10 100 1000 10000 Return Period (Year)

Figure C-6: Frequency Analysis of Annual Floods m Sg. Padas at Tenom (1969-2006)

95 SUNGAI SEGAMA AT LIMKABUNG Location

Description by DID, SABAH Summary of Data

Station No. 5181401 Name Sg. Segama at Limkabung SUNGAI SEGAMA AT LIMKABUNG 2 Area (km ): 2450 Elevation (m): 168 Gauging site:~ Gauging by boat Average Rainfall (mm) Longitude & Latitude:~ !'!8"07'50" E 05"07"25"" N. Water Use 2 Catchment Area:- 2450 km Total Mean yearly (m 3/s): 101.86 Elevation above mean sea level:- 168m Mean of"Min"s yearly (m 3/s) 14.11 3 Catchment characteristics:- Mean of"Max"s yearly (m /s): 977.73 3 (a) Shape:- The maximum length and breadth of the Absolute Min, yearly (m /s): 1.53 3 catchment are 85 km and 48 km respectively Absolute Max yearly (m /s): 2063.3 (b) Topography: - Low undulating hills predominate with Hydrological Records for some mountain in the upper catchment. Sabah, 1968-1975, DID Sabah (c) Vegetation :-Virgin and secondary jungle and shifting Source cultivation and other crops Streamflow and River (d) Soil Cove•·: - Ferric, chromic and orthic Lewisol, eutric Suspended Sediment cambisol Jithosol. Records,l975-1990, DID, Malaysia (e) Rock Type: - Southem part of catchment: Basic and intermediate igneous rock. Northern part of catchment: Mudstone and sandstone. Upper catchment: Mudstone and Sandstone

Ranged of observations: - The range of river stages observed is from 14.93 m to 22.9Jm. Discharge measurements have been taken between 15.09m and 20.61 m

96 [=!=Annual Mean -111-Annual Flood--Annual Drought I

0

Year

Figure C-7: Annual Discharge of Sg. Segama at Limkabung (1978-2006)

-+-Plotting Position ~Pearson Ill Log-Normal 3 I I Log-Pearson Ill -r-Gumbel Type I -e- Log-Normal L____j

10 100 1000 10000 Return Period (Year)

Figure C-8: Frequency Analysis of Annual Floods in Sg. Segama at Limkabung (1977- 2006)

97 SUNGAI WARLU AT JAMBATAN N0.2

Description by DID, SABAH Snmmary of Data

Station No. 6364401 Sungai Warlu at Jambatan SUNGAI WARLU AT JAMBATAN N0.2 Name no.2 2 Area (km ): 243 Gauging site:- Gauging by boat Elevation (m): 37 Longitude & Latitude:· 116'29'00" E 06'19'20"N. Average Rainfall (mm) Catchment Area:- 243 km 2 Water Use 3 Elevation above mean sea level:- 37m Total Mean yearly (m /s): 18.58 3 Catchment characteristics:- Mean of"Min"s yearly (m /s) 2.66 3 (a) Shape:- The max1mum length and breadth of the Mean of"Max"s yearly (m /s): 551.95 Absolute Min, yearly (m 3/s): 0.63 catchment are 25 km and 12 km respectively Absolute Max yearly (m 3/s): 1457.7 (b) Topography 30% undulating hills and 70% Hydrological Records for mountainous with elevations up to 3000 m Sabah, 1968-1975, DID (c) Vegetation: - Rubber trees, grassland, secondary jungle Sabah and upland vegetation. Source (d) Soil Cover: - Shallow granitic soil in the mountains with Streamflow and River sand and loam of2-3m deep in the hills Suspended Sediment Records, 1975-1990, DID, (e) Rock Type: -Sandstone and shale with shump breccia Malaysia in the lower catchment and ultrabasic granite in the upper catchment

Ranged of observations:- The range of river stages observed is from 25.06 m to 36.03m Discharge measurements taken between 25.78m and 26.51 m

98 I-+- Annual-Mean __,._Annual Flood Annual Drought ]

200~~~-2-2~--~~~~~~~~~~~~~~

0~~~~~~~~~~~~~~~~~~~~~¥~

Year

Figure C-9: Annual Discharge of Sg. Warlu at Bridge no.2 (1969-2006)

-+-Plotting Position (Weibull) ·-·•-- Pearson Ill Log-Normal 3 ~~"'~--log-Pearson Ill I -+-Gumbel Type I ----Log-Normal 2 I

10

10 100 1000 100':10 Return Period (Year) Figure C-1 0: Frequency Analysis of Annual Floods in Sg. Warlu at Bridge no.2 (1969- 2006)

99 SUNGAI KEDAMAIAN AT TAMU DARAT Location

Description by DID, SABAH Summary of Data

Station No. 6264401 Sg. Kedamaian at Tamu SUNGAI KEDAMAIAN AT T AMU DARAT Name Darat 2 Area (km ): 338 Gauging site:- \90 m Cableway Elevation (m): 52 Longitude & Latitude: - 116°27' I 0" E 06'15'50"N. Average Rainfall (mm) Catchment Area:- 338 km 2 Water Use I 3 Elevation above mean sen level:- 52 m Total Mean yearly (m /s): 32.4 3 Catchment characteristics:- Mean of"Min"s yearly (m /s) 3.28 3 (a) Shape:- The max1mum length and breadth of the Mean of"Max"s yearly (m /s): 855.14 3 catchment are 25 km and 15 km respectively Absolute Min, yearly (m /s): 0.72 Absolute Max yearly (m 3/s): 1574.2 (b) Topography: - 10% undulating hills and 90% Hydrological Records for mountainous with elevations up to 4000 m Sabah, 1968-1975, DID (c) Vegetation: - Padi, rubber trees, grassland, secondary Sabah jungle and highland altitude vegetation. Source (d) Soil Cover: - Shallow granite and granitic soil in the Streamflow and River mountains with sand and loam of2.3m deep in the hills Suspended Sediment Records, 1975-1990, DID, (e) Rocl• Type: - Sandstone, shale with shump breccia in Malaysia the upper catchment, ultrabasic

Hanged of observations: -The range of river stages observed is from 23.70 m to 27.08m. Discharge measurements taken between 23.75m and 25.51 m

100 !-+-Annual Mean --111-Annual Flood Annual Drought I

1800 -----·------;-- .. . 1600 ' . ·. _ .•. . ,/ • .· ·- l'\ " .. 1400 . · .. ..,~ 1200 /'\. -- 1. "' f .s 1000 1\ ~ "' !\. Gl " \ • ·--··- ~ I IV ~ ·_\ "' 800 .. \ . ~ J:"' r -~ .. ·- 600 !'\ l\r..J \I " "' •\!j ---··---· i5"' •.. \!1 II ·._ -· 400 .I J /'"'.I ,/ . ·--~-- 'rl 200 -· .---~-- •• ·- . .- ..· . . ·. - . ill~--~~.:;..-~.,...._.,..,...... ~-·~,.··~~~~~ ... ~--~. • ...... , ,. II\-- 0 --r-•• . . -·.· ··.· ' -'- ' -.- ' .- . _· " -~

Year

Figure C-11: Annual Discharge ofSg. Kedamaian at Tamu Darat (1969-2006)

-+-Plotting Position (weibul!) _._Pearson Ill Log-Normal 3 log-Pearson !II ...... Gumbel Type I -+-Lo -Normal 2 100000

10000

- 1000 ~ ~ •2' !! 0 .•c

10 100 1000 10000 Return Period (Year) Figure C-12: Frequency Analysis of Annual Floods in Sg. Kedamaian at Tamu Darat ( 1969-2006)

101 SUNGAI TUARAN AT MALANGGANG Location

Description by DID, SABAH Summary of Data

Station No. 6162401 Name Sg Tuaran at Malanggang SUNG AI TUARAN AT MALANGGANG 2 Area (km ): 564 Elevation (m): 45 Gauging site:- 85 m Cableway Average Rainfall (mm) Longitude & Latitude:-! 16"16'20" E 06'06'10"N. Water Use 2 Catchment Area:- 564 km Total Mean yearly (m 3/s): 43.48 Elevation above mean sea level:- 45 m Mean of 11 Min"s yearly (rn 3/s) 4.69 Catchment characteristics:- Mean of"Max"s yearly (m 3/s): 1202.45 3 (a) Shape:- The maximum length and breadth of the Absolute Min, yearly (m /s): 0.16 3 catchment are 35 km and 30 km respectively Absolute Max yearly (m /s): 3040.20 (b) Topography: - Mostly mountainous with elevations of Hydrological Records for up to 1660m Sabah, 1968-1975, DID Sabah (c) Vegetation: - Padi, rubber trees, secondary jungle and Source shifting cultivations Streamflow and River (d) Soil Cover: -Sandy to clayey loams of 1-3 m deep Suspended Sediment (c) Rocl< Type: - Sandstone and shale Records, 1975-1990, DID, Malaysia

Ranged of observations:- The range of river stages observed is from 28.46 m to 34.47m

102 1-+-- Annual Mean ---Annual Flood Annual Dr~

3500

~ 2500 +------~--~------~~~~~7---~~~~~~~~~ g2000+-~----~----~~~~~~~~~~~--~~~~~ "l:' ~ 1500+-----~~~--~~~~~~~~~~+-~~~~~~~~~ ~ 0 1000i~--,L----~~L------~~~~-----h----~~~ 500

0 ·-- co 0 ~ .... (j) 1'- co 0 ~ (j) "'(j) 1'- 1'- "'1'- 1'-"' 1'- 1'-"' 1'- 1'- 1'- 1'-"' co co "'co "'co "'~ "'~ "' "' "'~ "'~ "' "' "'~ "'~ "' "' "'~ "'~ "'~ "'~ Year

Figure C-13: Annual Discharge of Sg. Tuaran at Malanggang (1969-1982)

-+-Plotting Position (weibull) ·-II- Pearson Ill Log-Normal 3 I L Log-Pearson Ill --*--Gumbel Type 1 -e- Log-Normal 2 . '~~ =~_j!l~t~~~-~-

~ 1000 --,:_- i~ - _- '1,-~ :- =~~J+[~--- T 1-itll= -=: -~- ~~~=--,-1:--D-=~j:::I J i-=,-_ ~ 100 ~--- ~-=J~i~1=j :§t~=-~~:~~=jii~~~-:~~~~: 11=1~~~- ~=+~~~-~

10

i

I··· I 1 1-1,, .. 1: 1· -- 1-r trlt--~--n~~ -:-r, h~~--- 1 1T ',,,' I I ~''''' I I 10 100 1000 10000 Return Period (Year)

Figure C-14: Frequency Analysis of Annual Floods in Sg. Tuaran at Malanggang (1969- 1982)

103 SUN GAl TUNGUD AT BASAl Location

Description by DID, SABAH Summary of Data

Station No. 6073401 Name I Sg. Tungud at Basai SUNGAI TUNGUD AT BASAl Area (km'): 564 Elevation (m): 24 Gauging site: -Gauging by boat. Average Rainfall (mm) Longitude & Latitude: - I IT 18'30" E 06'03'00" N. Water Use 2 Catchment Area:- 564 km Total Mean yearly (m 3 /s): 43.0 Elevation above mean sea level:- 24 m Mean of"Min"s yearly (m 3/s) 4.37 3 Catchment char11cteristics:- Mean of"Max"s yearly (m /s): 782.24 3 (a) Shape:- The maximum length and breadth of the Absolute Min, yearly (m /s): 0.89 3 catchment are 50 km and 20 km respectively Absolute Max yearly (m /s): 1516.8 (b) Topography:- Hills with elevation up to 400m. Hydrological Records for (c) Vegetation: - Virgin and secondary jungle with some Sabah, 1968-1975, OlD Sabah shifting cultivations Source (d) Soil Cover: -Clayey loams of2-3 m deep Streamflow and River (e) Rocl• Type: -Sandstone and mudstone in the north side Suspended Sediment of the catchment and in the south side of catchment the Records, 1975-1990, DID, gabbro, chert and basalt. Malaysia

Ranged of observations:~ The range of river stages observed is from 22. I 5 m to 86.89m. Discharge measurements have been taken between 22.l9m and 23.8 I m

104 I-+- Annual Mean _....._Annual Flood Annual Drought I

1600.00 ----~----~------· 1400.00 --- r~---A~ 1200.00 u; \I i 1000.00

~ 800.00 .r::~ u ~ 600.00 0 400.00

200.00 ----~----~~~-

0.00

Year

Figure C-15: Annual Discharge ofSg. Tungud at Basai (1969-2006)

--+--Plotting Position (Weibull) ---Pearson Ill Log-Normal 3 I _.-.·Log-Pearson Ill __._Gumbel Type I -+--Log-Normal 2 I

i..... 1000

10 100 1000 10000 Return Period (Year) Figure C-16: Frequency Analysis of Annual Floods in Sg. Tungud at Basai (1969-2006)

105 SUNGAI LIWAGU AT BEDUKAN Location

Description by DID, SABAH Summary of Data

Station No. 5966401 Name Sg. Liwagu at Bedukan 2 SUNGAI LIWAGU AT BEDUKAN Area (km ): 440 Elevation (m): 430 Gauging site:- Gauging by boat Average Rainfall (mm) Longitude & Latitude:- I !6"39'10" E 05'55'00" N. Water Use 2 Catchment Area:- 440 km Total Mean yearly (m3/s): 4.96 Elevation above mean sea level:- 430 m Mean of"Min"s yearly (m 3/s) 0.49 3 Catchment characteristics:- Mean of"Max"s yearly (m /s): 87.55 3 (a) Shape:- The maximum length and breadth of the Absolute Min, yearly (m /s): 0.01 3 catchment are 20 km and 30 km respectively Absolute Max yearly (m /s): 298.67 (b) Topography: - Mountainous with elevations of up to Hydrological Records for Sabah, 1968-1975, DID 4000m Sa bah (c) Vegetation: - Padi and various other crops, virgin and Source secondary jungle Streamflow and River (d) Soil Cover: - Sandy loam in varying depths and in the Suspended Sediment upper catchment, shallow granitic soils. Records, 1975-1990, DID, Malaysia (c) Rock Type: - Sandstone and shale and in the upper catchment, ultrabasic and granite

Ranged or observations:- The range of river stages observed is from 26.52 m to 30.59m

106 -+-Annual Mean --Annual Flood Annual Drought

350 -----·----

300

"';;; 250 .§. 200 Q) E' ~ 150

i5""' 100 50

a+-~'~' 0> CD 0> Year

Figure C-17: Annual Discharge of Sg. Liwagu at Bedukan (1970-1980)

-+-Plotting Position (Weibull) ...... _._Pearson Jll log-Normal 3

I :-. Log-Pearson Ill _..Gumbel Type I __.._log-Normal 2

-;;; £ "• ~ 100

~• u .•c

10

10 100 1000 10000 Return Period (year)

Figure C-18: Frequency Analysis of Annual Floods in Sg. Liwagu at Bedukan (1970- 1980)

107 SUNGAI LABUG AT POROG Location

Description by DID, SABAH Summary of Data

Station No. 5872401 Name Sg. Labuk at Porog SUNG AI LABUK AT POROG 2 Area (km ): 3240 Elevation (m): 17 Gauging site:- Gauging by boat Average Rainfall (mm) Longitude & Latitude: -117"13'40" E OS'SJ'IS"N. Water Use 2 Catchment Area:- 3240 km Total Mean yearly (m 3/s): 185.76 Elevation above mean sea level:- I 7 m Mean of"Min"s yearly (m 3/s) 37.16 Catchment characteristics:- Mean of"Max"s yearly (m3/s): 1806.34 3 (a) Shape:- The maximum length and breadth of the Absolute Min, yearly (m /s): 4.1 3 catchment are 95 km and 60 km respectively Absolute Max yearly (m /s): 3534.4 (b) Topography: - 10% undulating hills with elevations Hydrological Records for Olround 200m. 50% hills with elevations around 4000m. Sabah, 1968-1975, DID Sabah (c) Vegetation: - Padi and various other crops and also Source virgin and secondary jungle rubber trees, secondary Streamflow and River jungle and shining cultivations Suspended Sediment (d) Soil Cover: -Sandy to clayey loams of 1-3 m deep Records, 1975-1990, DID, (e) Rock Type: - Sandstone and shale Malaysia

Ranged of observations:- The range of river stages observed is from 28.46 m to 34.47m

108 -+---Annual Average -----Annual Flood Annual Drought

4000 ------"-- -- ~- -~------3500 ------~----- 3000

(") "'-E. 2500 Q) Cl 2000 ~ .:: "'() 1500 i5"' 1000 500 0

Year

Figure C-19: Annual Discharge of Sg. Labug at Porog (1969-2006)

--+-Plotting Position (Weibull) ...... __Pearson Ill Log-Normal 3 I Log-Pearson Ill --*-Gumbel Type I -+-Log-Normal 2 I 100000

1 -, --_ ~-: =-=~------i ~~l _ ---~---==l l---~-==--==R=;=- I n ~-'t-~~~rili1HFFm~_- -~- -- --·l- --~- : I-:T1 -: - L_ -1- -,-n-n 10000 , Ii it==-( J-"; £u-J ==.=~- --=El = tk- -~~~ l= -~~ _e L I '" , ~- l=ft , T- 11 ~~r --H c- -:--~ ---- -r---~-- -~-~ .. 1000 -: tr-- - -~---1 ):=Fr~r-=------~~~~='~------1 I 1 F""f-~~~~=:~~~~--- c:cct:=±=-1------~~~~=~f,=-=!::=- "g r -, r- r ------, ~ -r - - ~- --, 1 ______L__ - -,-l- • ------+-+--1-1- --- -~-- -- ~ - I I l f iffi ------_:fl~i I~,-_:~-::: I ~~--:_ f----~------~• .•0 c 100 ~3'C~~ic :-~~jl~~~~ :Ji:=c1-j;:~)i _,_, ___ F "''':' -f+=:-~~:~--_-,_: ~r-" , =, 1 II - • ' I I I I , ' , -- -- I + I 1 ~-j -- i - . I' d'- -- 10 ' h : ·-~~·' - -~- ~);J -~=--~ ~=~=j= ='~-~~ ==-:: -~-~~::_1_ ~ I-~-·- -·j_l,- - l:c--1-- I =, __:---:::c:---r--·- _l_:= __--_-j_j_ __ cJ --'1 r i I _ I 1 __ -L- __ _ r _ _ 1 __ _ -l- I _L 1 1 1 1 4 i 1 . 1 1: 1 - 1 ~ l•1=r - 1- ~ I ·-f=-=t 1 t-: 1 if! 1 1 10 100 1000 10000 Return Period (Year)

F1gure C-20: Frequency Analys1s of Annual Floods 10 Sg. Labug at Porog

109 SUNG AI LAB UK AT TAMPIAS Location

Description by DID, SABAH Summary of Data

Station No. 5768401 Name Sg, Labuk at Tampias SUNGAI LABUK AT TAMPIAS, 2 Area (km ): 2010 Elevation (m): 168 Gauging site:- Gauging by boat Average Rainfall (mm) Longitude & Latitude: - 116•5 I '35" E 05'43'05" N. Water Use I 2 Catchment Area:- 2010 km Total Mean yearly (m 3/s): I 06.65 Elevation above mean sea level:- 168m Mean of"Min"s yearly (m 3/s) 21.37 Catchment characteristics:- Mean of"Max"s yearly (m 3/s): 1270.34 3 (a) Shape:- The maximum length and breadth of the Absolute Min, yearly (m /s): 1.77 3 catchment are 58 km and 52 km respectively Absolute Max yearly (m /s): 2882.9 (b) Topography: - Mountainous with elevations of up to Hydrological Records for 4000m in the upper catchment Sabah, 1968-1975, DID Sabah (c) Vegetation:- Padi with various other crops and shifting Source cultivation. Virgin and secondary jungle Streamflow and River (d) Soil Cover: - Sandy loams of varying depths and in the Suspended Sediment upper catchments, shallow granitic soil Records, 1975-1990, DID, (e) Rock Type: Sandstone, shale and in the upper Malaysia catchment, ultrabasic and granite

Ranged of observations: ~The range of river stages observed is from 0.78 m to ll.9lm. Discharge measurements taken between6.83mand 7.15 m

II 0 --+--Annual Mean ..---.4----- Annual Flood' Annual Drought

3500

3000

2500 --­ "';;; _§_ 2000 ~ ~ 1500 0 i5 1000-

500

o L~''=.='.'==".~- :=+.="=. ==+-. __.___, "'.'==='.'==". ~-:=+::.:::"o_ -+:::.-..~.=---*. ----. --.,.____ ---~, ~~~

Year

Figure C-21: Annual Discharge of Sg. Labuk at Tampias (1977-2006)

-+---Plotting Position (weibull) ------Pearson I! I Log-Normal 3 Log-Pearson !II """'*-Gumbel Type I ...... _.Log-Normal 2

10 100 1000 10000 Return Period (year)

Figure C-22: Figure Frequency Analysis of Annual Floods in Sg. Labuk at Tampias (1977-2006)

I II SUNG AI PAPAR AT KOGOPON Location

Description by DID, SABAH Summary of Data

Station No. 5760401 Name Sg. Papal at Kogopon SUNGAI PAPAR AT KOGOPAN 2 Area (km ): 357 Elevation (m): 91 Gauging site:- 76 m Cableway Average Rainfall (mm) Longitude & Latitude: - 1!6"05'30" E 05'46"10"" N Water Use 2 Catchment Area:- 357 km Total Mean yearly (m 3/s): 24.24 Elevation above mean sea level:- 9-1 m Mean of"Min"s yearly (m 3/s) 3.48 Catchment characteristics:- Mean of"Max"s yearly (m3/s): 438.24 3 (a) Shape:- The maximum length and breadth of the Absolute Min, yearly (m /s): 0.86 catchment are 25 km and 20 km respectively Absolute Max yearly (m 3/s): 1550.6 (b) Topography: - Mostly mountainous with elevations of Hydrological Records for

up to 1500m Sabah, 1968-1975, DID Sa bah (c) Vegetlltion:- Secondary jungle and shifting cultivations Source (d) Soil Cover: - Sandy to clayey !oams of l-3 m deep Streamflow and River (e) Rock Type: - Sandstone and shale Suspended Sediment Records,l975-1990, DID, Malaysia

Ranged of observations:- The range of river stages observed is from 25.9! m to 30.29m. Discharge measurements taken between 25.9lm and 26.95 m

112 I-+- Annual Mean ----Annual Flood . Annual Droug££]

1800 1600 1400

M 1200 -"'.§. 1000 "' ~ 800 J:: "'() en 600 0 400 200 0

Year

Figure C-23: Annual Discharge ofSg. Papar at Kogopan (1969-2006)

-+-Plotting Position (Weibull) -11- Pearson Ill log-Normal 3 r Log-Pearson Ill -+--Gumbel Type I -+-Log-Normal 2

10 100 1000 10000 Return Period (year)

Figure C-24: Frequency Analysis of Annual Floods in Sg. Papar at Kogopan (1969-2006)

113 SUNGAI PAPARAT KAIDUAN Location

Description by DID, SABAH Summary of Data

Station No. 5760402 Name Sungai Papar at Kaiduan SUNGAI PAPAR AT KAIDUAN 2 Area (km ): 536 Elevation (m): 24 Gauging site:- 116m Cableway Average Rainfall (mm) Longitude & Latitude:- 116"02'10" E 05'42'30" N. Water Use 2 Catchment Area:- 536 km Total Mean yearly (m3/s): 43.18 Elevation above mean sea level:- 24m Mean of"Min"s yearly (m 3/s) 6.48 Catchment characteristics:- Mean of"Max"s yearly (m 3/s): 814.13 3 (u) Shape:- The max1mum length and breadth of the Absolute Min, yearly (m /s): 1.33 3 catchment are 35 km and 20 km respectively Absolute Max yearly (m /s): 2477 (b) Topography: - Mountainous with elevations of up to Hydrological Records for ISOOm Sabah, 1968-1975, DID Sa bah (c) Vegetation: -Secondary jungle, shifting cultivations and Source rubber trees Streamflow and River (d) Soil Cover: - Sllndy to loams of 1-3 m deep Suspended Sediment (e) Rocl' Type: - Sandstone and shale Records, 1975-1990, DID, Malaysia

Ranged of observations:- The range of river stages observed is from 25.14 m to 30.72m. Discharge measurements have been taken between 25.83m and 27.20m

114 I-+- Annual Mean _.,_Annual Flood Annual Drought I

3000

2500

~ ..!!! .sM 2000 1500 "'~ J:"' " 1000 i:5"' 500

0

Year

Figure C-25: Annual Discharge ofSg. Papar at Kaiduan (1969-2006)

-+-Plotting Position (Weibull) --tt-Pearson Ill Log-Normal 3 Log-Pearson Ill -+-Gumbel Type I -+-Log-Normal 2 100000

10000

~ 1000 g • •E' ~ i5

10 100 1000 10000 Return Period (Year) Figure C-26: Frequency Analysis of Annual Floods in Sg. Papar at Kaiduan (1969-2006)

115 SUNGAI MILIAN AT TANGKULAP Location

""'"'.s()'f4ilo1 ,•

Description by DID, SABAH Summary of Data

Station No. 5373401 Sungai Millian at SUNGAI MILIAN ATTANGKULAP Name Tangkulap Area (km'): 5730 Gauging site:~ Gauging by boat Elevation (m): 25

Longitude & Latitude: ~ II T I 9'05" E 05'18'15"N. Average Rainfall (mm) Catchment Area:- 5730 km 2 Water Use Nil 3 Elevation above mean sea level:- 25 m Total Mean yearly (m /s): 227.55 3 Catchment characteristics:- Mean of"Min"s yearly (m /s) 24.09 11 11 3 (a) Shape:- The maximum length and breadth of the Mean of Max s yearly (m /s): I 085.3 3 catchment are 95 km and 80 km respectively Absolute Min, yearly (m /s): 2.79 3 (b) Topography: - 80% hill with elevations around 600m Absolute Max yearly (m /s): 2413.6 and 20% mountainous with elevation up to 2600m Hydrological Records for Sabah, 1968-1975, DID (c) Vegetation: - Virgin and secondary jungle with some Sabah shifting cultivation. Source (d) Soil Cover:- Hills, covered with sandy loam of 1-3 M Streamflow and River deep. Mountains covered with nne to coarse sand and Suspended Sediment Records,J975-1990, DID, shallow in depth Malaysia (e) Rock Type: - Mudstone, sandstone, and in the north side of the catchment, chert, basalt and gabbro

Ranged of observations: - The range of river stages observed is tTom 12.32 m to 26.68m. Discharge measurements have been taken between 12.40m and 23.08m

116 -+-Annual Mean -~t-Annual Flood Annual Drought

3000 ------~---~~------~- ---~ .. ·~ -··~·-- ~ ------~ ---~~----~·-~--

2500 ~ ~ -~-- ~------ii) -sM 2000 Cl 1500 - "'~ .<:"' 1000 i5""' 500 -

0

Year

Figure C-27: Annual Discharge ofSg. Milian at Tangkulap (1969-2006)

-...-Plotting Position (Weibull) ...... __Pearson Ill Log-Normal3 I

I - Log-Pearson Ill --Jr Gumbel Type I ...... ,... Log-Normal2

10 100 1000 10000 Return Period (Year) Figure C-28: Frequency Analysis of Annual Floods in Sg. Milian at Tangkulap (1969- 2006)

117 SUNG AI SOOK AT BlAH Location

Description by DID, SABAH Summary of Data

Station No. 5261402 Name Sungai Soak at Biah SUNGAI SOOK AT BlAH 2 Area (km ): 1684 Elevation (m): 260 Gauging site:- 45 m Cableway Average Rainfall (mm) Longitude & Latitude:- 116"08'25" E 05'15'25" N. Water Use Nil 2 Catchment Area:- 1684 km Total Mean yearly (m 3/s): 24.53 Elevation above mean sea level:- 260 m Mean of"Min"s yearly (m3/s) 2.25 Catchment characteristics:- Mean of"Max"s yearly (m 3/s): 180.72 3 (o) Shape:- The maximum length and breadth of the Absolute Min, yearly (m /s): 0.39 3 catchment are 45 km and 75 km respectively Absolute Max yearly (m /s): 357.49 (b) Topography: - Terraces with elevations around 500m Hydrological Records for and some mountains with elevation of up to 1500m. Sabah, 1968-1975, DID Sabah (c) Vegetation: - Grassland, virgin and secondary jungle Source with some shifting cultivations and rubber trees. Streamflow and River (d) Soil Cover:- Find to coarse sand, loam of2-5 m deep Suspended Sediment (e) Rocl{ Type: - South side of the catchment : Sandstone Records, 1975-1990, DID, mudstone, North side of catchment . Alluvial gravel Malaysia

Rilngcd of observations:- The range of river stages observed is from 25.46 m to 29.30m

118 j-+-Annual Mean ---Annual Flood Annual Drought j

400.00

350.00 ------

" 300.00 ------,~ ______]. z5o.oo ---r\_:;;------1 i;:: J~-~rtv~~ ------~------50.00

0.00- -,-,-,-.-.-.-,-.-.

Year

Figure C-29: Annual Discharge of Sg. Sook at Biah (1969-2006)

--+-Plotting Position (weibull) --11-- Pearson Ill Log-Normal 3 I - Log-Pearson Ill ...... -Gumbel Type! ...... _ Log-Normal2

10 100 1000 10000 Return Period (Year)

Figure C-30: Frequency Analysis of Annual Floods m Sg. Sook at B1ah (1969-2006

I I 9 SUNGAI PEGALAN AT ANSIP

Description by DID, SABAH Summary of Data

Station No. 5261401 Name Sungai Pegalan at Ansip SUN GAl PEGALAN AT ANSIP 2 Area (km ): 2175 Elevation (m): 230 Gauging site:- 60 m Cableway Average Rainfall (mm) Longitude & Latitude:- 116"06'25" E 05'16'55" N. Water 0.86 Ml/day Catchment Area:- 2175 km 2 Use 1.30 Ml/day 3 Elevation above mean sea level:- 230 m Total Mean yearly (m /s): 52.03 3 Catchment characteristics:- Mean of"Min"s yearly (m /s) 10,78 3 (a) Sh11pc:- The maximum length and breadth of the Mean of"Max"s yearly (m /s): 400,57 3 catchment arc 70 km and 45 km respectively Absolute Min, yearly (m /s): 1.96 Absolute Max yearly (m 3/s): 1379.6 (b) Topography: 30% Alluvial Valley with elevation of Hydrological Records for 400-600 m and 70% mountainous with elevation up to Sabah, 1968-1975, DID 2600m Sa bah (c) Vegetation: - Padi and various other crops, grassland Source: virgin and secondary jungle Streamflow and River

(d) Soil Cover: - Mountainous: Sandy loam of 1-2m deep. Suspended Sediment Records,1975-1990, DID, Alluvium: Various textures in layers of 10-20 m deep. Malaysia (e) Rock Type: Sandstone, mudstone and mudstone predominant in the upper catchment

Ranged of observations:- The range of river stages observed is from 17.21 m to 25.30m

120 -+--Annual Mean _..__Annual Flood Annual Drought

1600 ... ·---··---···-- ·-·---·--.---·

1400 ··--·-····· ------..... ~

, 1200 __ ... -·--·------~~~=-~ ~--- --=-- ·r=- 11000 r I

~,,__..._.,__.. 0 ,-,-.-, -,-,-.-,-,-.-,-,-,-,--,-,-,-.-.-,-,-.-.-.-,-,-,-,- -,-,-,-,-.-.-,-,--,

Year

Figure: C-31: Annual Discharge of Sg. Pegalan at An sip (1969-2006)

--w- Pearson Ill Log-Normal 3 ~Gumbel T pe I --- Lo -Normal 2 100000

10000 ~ 1000 ~Cf"~-·--~~ ~r~~~~~-c~~~[f~l~~ 1,"-~=;--f:=lCf~:H!~~:~J§~~ ~~=~1=-~~f~~ ;_~I ~~·~-~-r-~-;tt-t· ~:·~~-, ' c,; I- i : ~ "r=f T,--:-·-t i5 100 _- T f j p~~-- --~-~1 =F • • ±= i= I ,_ ~~;c,flffcrtr!~c r~ :-nq~; ' .1 10 ~-+ ~.- i· . : ~ll ~~= ~ ... ~ T} Ill=~~ c. . -~,~~f~ll-~ ~F~=1~f]j - I ; I. ~_:::_: I-I f.+. _::::::;~::::::]·1·~~~~~.. ~ --....- ··f-~~-~ i.lj I I I I I I I - ,- ' I ~--, ____J__T - +---.J__L~..c_l..LL:J..l I I I : I I I I I i I I ! i I 10 100 1000 10000 Return Period (Year) Figure C-32: Frequency Analysis of Annual Floods in Sg. Pegalan at Ansip (1969-2006)

121 SUNGAI TAWAU AT KUHARA Location

Description by DID, SABAH Summary of Data

Not Available Name Sungai Tawau at Kuhara 2 Area (km ): 104 Elevation (m): - Average Rainfall (mm) - Water Use Total Mean yearly (m 3/s): 3.28 Mean of"Min"s yearly (m3/s) 1.03 Mean of "Max"s yearly (m 3/s): 27.02 Absolute Min, yearly (m3/s): 0.13 Absolute Max yearly (m 3/s): 62.30 Softcopy Streamflow Data Source: 1969-2006, DID, Sabah, Malaysia

122 -+--Annual Mean -a-Annual Flood Annual Drought

70 60 --!'a VI 50 ;:; .s.., 40 :d! __= ----- E' .E 30 i5""' 20

10

0 -----,---,-,~

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~NNNNNNNN illillillillillillillillillillillillillillillillillillillillWWWWillillillillillillWWillOOOOOOOO mmm~~~~~~~~~~~oooooooooooooooooowwwwwwwwwwoooooooo ~oowo~Nw~~m~oowo~Nw~~m~oowo~Nw~~m~oowo~Nw~~m~ Year

Figure C-33: Annual Discharge ofSg. Tawau at Kuhara (1969-2006)

-+--Plotting Position (weibull) ---Pearson Ill Log-Normal 3 Log-Pearson lll ""'"*-Gumbel Type I ---Log-Normal 2

100

~ §. •e> ~• 0 ••0

10

10 100 1000 10000 Return Period (Year)

Figure C-34: Frequency Analysis of Annual Floods in Sg. Tawau at Kuhara (1969-20(·~)

123 SUNGAI BALUNG AT BALUNG BRIDGE Location

Description by DID, SABAH Summary of Data

Not Available Sungai Balung at Balung Name Bridge 2 Area (km ): 2175 Elevation (m): 230 Average Rainfall (mm) Water 0.86 Mil day Use 1.30 Mil day Total Mean yearly (m 3/s): 3.93 Mean of "Min"s yearly (m 3/s) 0.52 Mean of"Max"s yearly (m 3/s): 83.48 Absolute Min, yearly (m 3/s): 0.06 Absolute Max yearly (m 3/s): 213.19 Softcopy Streamflow Data Source: I 969-2006, DID, Sabah, Malaysia

124 ---+-Annual Mean --~~-'--Annual Flood Annual Drought

250 ------

200 ~ .§. 150

"'~ ~ 100 " i5"' 50 -

0 ------~ N ..,. 1'- co 0) 0 ~ N ..,. .... 0) 0) 0) 0) 0) 0) 0) 0) 0) 0 0 0 0 0 0 0 0 0) 0) "'0) 0) 0)"' "'0) 0) 0) 0) 0 0 0 "'0 0 0"' "'0 0 ~ ~ N N N N N N N N Year

Figure C-35: Annual Discharge ofSg. Balung at Balung Bridge (1992-2006)

--+--Plotting Position (WElibull) ---Pearson Ill Log-Normal 3 I Log-Pearson Ill ...... Gumbel Type I -e- Log_:Normal 2 I

1000

10 100 1000 10000 Return Period (Year) Ftgure C-36: Frequency Analysts of Annual Floods m Sg. Balung at Balung Bndge ( 1992-2006)

ns SUNGAI KALABAKAN AT KALABAKAN Location

Description by DID, SABAH Summary of Data

Not Available Sungai Kalabakan at Name Kalabakan 2 Area (km ): 1150 Elevation (m): - Average Rainfall (mm) Water Use Total Mean yearly (m 3/s): 32.63 Mean of 11 Min 11 s yearly (m 3/s) 1.69 Mean of 11 Max"s yearly (m 3/s): 695.56 Absolute Min, yearly (m 3/s): 0.53 Absolute Max yearly (m 3/s): 1401.2 Softcopy Stream flow Data Source: 1969-2006, DID, Sabah, Malaysia

126 j-.-Annual Mean ---Annual Flood Annual Drought j

1600 ------··------

1400 ------·------

~ 1200 ~ 'E 10oo ~ 800 fj"' 600 Ill i5 400

200 0

~ ~ ~ ~ ~ ~ ~ ~ ~ ~ <.0 <.0 <.0 <.0 <.0 <.0 <.0 <.0 <.0 <.0 <.0 <.0 <.0 <.0 <.0 <.0 0 0 0 0 0 0 0 0 <.0 <.0 <.0 <.0 <.0 <.0 "'0 "'0 "'0 "'0 "'0 0"' "'0 0"' _,. 0) ~ _,. 0) ~ _,. "' "' "' ..,"' "' "' 0 "' "'--J "' "' 0 0) --J "' "' "' "' "' "'Year "' "' "' "' "'

Figure C-37: Annual Discharge of Sg. Kalabakan at Kalabakan (1986-2006)

-+-Plotting Position (Weibull) __.._Pearson Ill Log-Normal 3 I "Log-Pearson Ill ....._Gumbel Type I -+--Log-Normal 2 100000 ~ -, ~b'4 Ff===' - - R != ------, I " j ----f I ~=;,I =-=*---,-c lt ttl -- _:___-' I - , td - ' -~- ~--__:--~ I i I '-1 =---~ -I -r=- -=--=-t~--?~.-L t- -m-ftj 10000 --~~=~-~~~~ ~ ---~--= __ l_c:~~~ _ ~-~~H- =l-llic-=~~~-tc.~r~l· I ' ' f ' I - =f= c _, --- • C1 ~ I --r C-'- ~------, 1 • r r · --; --(r___j j - - --~ 1 - ,li ii c -- F"" - ;-t- +-If+• 1 ::orr , 1000 .. "-= -~ ~=tf~' + ' I ---, cL ., ".§_ -~'""'"hi I'r~- c~lo, -~'#' t ' . • -----f:'+I ~~I- ~j , -----I- -r- TfI c - I• - _li.- - ' - + e- -~- 1-~- - ~~-- . -1 ~• -- - l - • . I -- I T 1 -- - -- I,____ 0 +- 1 ----1- - 1 5 100 -; ---c=- ' HI ' I - -=----• ---r- -- ' ~=-==c- ...3c=- ~ r -- ~ -- • - _1- -·-,f -~[~-=--1-~--- ~--- ,I -==-=---=F~fh--,- -- -- +l 1-~1- r·---- r ·-·r---- - I ; I I I ' I -----_I_! II - --- 1------: - I I I I I I I I' I ' 10 : 1 - - - .- -~--~1--1 _-- -f=F,---' 1 - _ __c r---c+J- _ - __ f=::__ ~ .-__ -~--=~= -_- _ -"-+~_,------1-1---f- _l ___ ~~----r-- . -- f· -, - •- !--- I ffi ' J f-ltc-1,---1-r -i-1- I: ---:-r-- I I ! i I • • I I I i II: I . . II 1 hl 1 10 100 1000 10000 Return Period (Year) Figure C-38: Frequency Analysis of Annual Floods m ofSg. Kalabakan at Kalabakan ( 1986-2006)

127 SUNGAI KALUMPANG AT MOSTYN BRIDGE Location

·'

Description by DID, SABAH Summary of Data

Not Available Sungai Kalumpang at Name Mostyn Bridge 2 Area (km ): 565 Elevation (m): - Average Rainfall (mm) Water Use Total Mean yearly (m 3/s): 22.37 Mean of"Min"s yearly (m 3/s) 4.02 Mean of"Max"s yearly (m 3/s): 681.78 Absolute Min, yearly (m 3/s): 0.1 Absolute Max yearly (m 3/s): 1820.1 Softcopy Streamflow Data Source: 1969-2006, DID, Sabah, Malaysia

128 l+- Annual Mean _,_Annual Flood Annual Drought

2000

1800 ------1600 :w 1400 .s"'., 1200 ------1-\-- E' 1000 J: BOO "'(J Vl iS 600 400

0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~NNNNNN ~~m~m~w~wwwwwwwwwwwwwwwwwwwwwwwwwooooooo mmm~~~~~~~~~~oooooooooooooooooooowwwwwwwwwwooooooo ~oowo~Nw~~m~oowo~Nw~~m~oowo~Nw~mm~oowa~Nw~mm Year

Figure C-39: Annual Discharge ofSg. Kalumpang at Mostyn Bridge (1969-2006)

10 100 1000 10000 Return Period (Year)

Ftgure c-40: Frequency Analysts of Annual Floods m Sg. Kalumpang at Mostyn Bndge (1969-2006)

129 SUNGAI SAPULUT AT SAPULUT Location

Description by DID, SABAH Summary of Data

Not Available Name Sungai Sapulut at Sapulut Area (km'): 2599 Elevation (m): - Average Rainfall (mm) Water Use Total Mean yearly (m3/s): 76.67 Mean of"Min"s yearly (m3/s) 11.78 Mean of"Max"s yearly (m 3/s): 900.31 Absolute Min, yearly (m 3/s): 4.89 Absolute Max yearly (m 3/s): 1836.6 Softcopy Streamflow Data Source: 1969-2006, DID, Sabah, Malaysia

130 -+---Annual Mean _,._Annual Flood Annual Drought

2000 ------~~~ 1800 1600 1400 :wM .§. 1200

Cl 1000 "'~ J:"' 800 i5""' 600

400 ------~~~~

200 ------~~--~-

0 .~.-.-.-.-,-.~.-.-.~,-.~.-.-.-.~.~ ~ N N N N <0 <0 <0 <0 0 0 0 0 t:l t:l <0 <0 <0 0 0 0 0 0 "'<0 0 0 ~ ~ Ol "' Year"' "' "'

Figure C-41: Annual Discharge of Sg. Sapulut at Sapulut (1990-2006)

~---r~~~~~~~======~=-===~~--+-Plotting Position (Weibull) ...... -Pearson Ill log-Normal 3

· .,. Log-Pearson Ill ~Gumbel Type I -+-Log-Normal 2 1

10

10 100 1000 10000 Return Period (Year) Figure C-42: Frequency Analysis of Annual Floods m Sg. Sapulut at Sapulut (1990- 2006)

131 SUN GAl TALANKAI AT LOTONG Location

Description by DID, SABAH Summary of Data

Not Available Name Sungai Talankai at Lotong 2 Area (km ): 652 Elevation (m): - Average Rainfall (mm) Water Use Total Mean yearly (m 3/s): 21.48 Mean of "Min"s yearly (m 3/s) 4.19 Mean of"Max"s yearly (m3/s): 349.72 Absolute Min, yearly (m 3/s): 0.75 Absolute Max yearly (m 3/s): 581.78 Softcopy Streamflow Data Source: 1969-2006, DID, Sabah, Malaysia

132 1-+-Annu~l Mean --11----Annual Flood

700

600

- 500 ------~ .§. 400 ------

\ L I -~ -~~~ ' ~ 100 --- _., ____ L ------

0 ~

~ ~ ~ ~ ~ 0" "0 "0 0 0 0 "0 0 "'_,. "' "' "' "' "' :1 0 "0 " "0 0 "0 ""' "'w "' "' "' "' "' "' 8 " w l< "' "' "' "' " "' Year "

Figure C-43: Annual Discharge ofSg. Talankai at Lotong (1993-2006)

-+-Plotting Position (Weibull) -a--Pearson Ill Log-Normal 3 > -Log-Pearson Ill -*-Gumbel Type I _._Log-Normal 2 I c

10 100 1000 10000 Return Period (Year) ~--~~~----~~~~--~~~~~~~~~--~~--­ Figure C-44: Frequency Analysis of Annual Floods in Sg. Talankai at Lotong (1993- 2006)

133 SUNGAI MENGALONG AT SINDUMIN

Description by DID, SABAH Summary of Data

Not Available Sungai Mengalong at Name Sindumin 2 Area (km ): 472 Elevation (m): . Average Rainfall (mm) Water Use Total Mean yearly (m3/s): 27.21 Mean of"Min"s yearly (m 3/s) 2.2 Mean of"Max"s yearly (m 3/s): 552.35 Absolute Min, yearly (m 3/s): 0.14 Absolute Max yearly (m3/s): 889.98 Softcopy Streamflow Data Source: 1969-2006, DID, Sabah, Malaysia

134 -+-Annual Mean _,__Annual Flood Annual Drought

1000

900 ------~---~---~-~------800 Iii 700 -M .§.., 600 E' 500 J:.. 400 i5""' 300 200 100 ------·-- - -- +---+--.. H- $1 .. h ~ • .. 0 • • • • • • • • ' • • • • • '---,---, ~ ~ ~ ~ ~ ~ ~ ~ ~ N N N N N N N N 0 0 0 0 0 0 0 0 0 00 00 00 00 00 00 00 00 00 0 0 0 0 0 0 0"' 0 0 "'~ ~ "' "' "' "' "' "' "' "' "' "' "' "' ~ N "'.... "' Ol 00 "'0 "' "'N "' ...."' "' "'Ol "' "'00 "' 0 N .... Ol 00 "' "' "" "' "' Year"' "" "' "' "' ""

Figure C-45: Annual Discharge of Sg. Mengalong at Sindumin (1982-2006)

-+-Plotting Position (Weibull) --11- Pearson Ill Log-Normal 3 Log-Pearson Ill ~Gumbel Type I _.,_Log-Normal 2

10 100 1000 10000 Return Period (Year) Figure C-46: Frequency Analysis of Annual Floods in Sg. Mengalong at Sindumin (1982-2006)

135 SUNGAI LAKUTAN AT MESAPOL Location

Description by DID, SABAH Summary of Data

Not Available Sungai Lakutan at Name Mesapol 2 Area (km ): 173 Elevation (m): - Average Rainfall (mm) Water Use Total Mean yearly (m 3/s): 9.45 Mean of"Min"s yearly (m3/s) 1.08 Mean of"Max"s yearly (m 3/s): 434.62 Absolute Min, yearly (m 3/s): 0.2 Absolute Max yearly (m3/s): 1388.3 Softcopy Streamflow Data Source: I 969-2006, DID, Sabah, Malaysia

136 -+-Annual Mean ---Annual Flood Annual Drought

1600 1400

- 1200 ·······-·---- *l ,§. 1000 - "E' 800 .:: "'() 600 -- i5"' 400 200

0 -h-"-'"-"--<'>-<'-"-~---,-.,~~~~~~---,--~--.-"'""-"-"-"---''-"-~~0-"-''-r-<

~~~~~~~~~~~4~~~~~~~~~~~~~~~~~~~~~NNNNNNNNN m~~wmwmwwwwwwwmwwwwwwwwwwwwwwwwwwooooooooo mmm~~~~~~~~~~oooooooooooooooooooowwwwwwwwwwooooooooo ~oowo~Nw~~m~oowo~Nw~~m~oowo~Nw~~m~oowo~Nw~~m~oo Year

Figure C-47: Annual Discharge of Sg. Lakutan at Mesapol (1969-2006)

-+-Plotting Position ...... Pearson Ill Log-Normal 3 I Log-Pearson Ill -+-Gumbel Type 1 -e-Log-Normal 2 I

10 100 1000 10000 Return Period (Year)

F1gure C-48: Frequency Analys1s of Annual Floods m Sg. Lakutan at Mesapol (1969- 2006)

137 SUNGAI KINABATANGAN AT PAGAR Location

'';/'"~4 ~,:z,

Description by DID, SABAH Summary of Data

Not Available Sungai Kinabatangan at Name Pagar 2 Area (km ): 9430 Elevation (m): - Average Rainfall (mm) Water Use Total Mean yearly (m3/s): 352.41 Mean of"Min"s yearly (m3/s) 35"64 Mean of"Max"s yearly (m 3/s): 1510"87 3 Absolute Min, yearly (m /s): 4"25 Absolute Max yearly (m 3/s): 2004 Softcopy Streamflow Data Source: 1969-2006, DID, Sabah, Malaysia

138 j--+-Annual Mean --ao- Annual Flood Annual Drought j

2500

2000 ~ .§.. 1500 "E' ~ 1000 lil 5 500

0 ' - • - • ------,--- ' - ' - . -----,----. I ------.---- I - I -

~ ~ ~ ~ ~ ~ ~ ~ ~ ~ m m m m m m m w w m w w <.0~ "'0 ru oo oo oo oo w w m m m m m m m <.0 0 ~ m ~ oo m o ~ N w ~ ~ m ~ oo <.0 0 Year

Figure C-49: Annual Discharge of Sg. Kinabatangan at Balat (1986-2006)

Retum Period (Year)

F1gure C-50: Frequency Analys1s of Annual Floods m Sg. Kmabatangan at Balat (1986- 2006

139 SUNGAI PADAS AT BEAUFORT JPS Location

Description by DID, SABAH Summary of Data

Not Available Sungai Padas at Beaufort Name JPS 2 Area (km ): 8500 Elevation (m): - Average Rainfall (mm) Water Use Total Mean yearly (m 3 /s): 220.43 Mean of"Min"s yearly (m 3/s) 24.13 Mean of"Max"s yearly (m 3/s): 960.29 Absolute Min, yearly (m 3/s): 1.04 Absolute Max yearly (m 3/s): 1535.4 Softcopy Streamflow Data Source: 1969-2006, DID, Sabah, Malaysia

140 ----+--Annual Mean --11--Annual Flood ------Annual Drought

1800.00 1600.00 1400.00 ~ 1200.00 .§. ., 1000.00 E' 800.00 - .<:"' 600.00 i5"'" 400.00 - 200.00

Year

Figure C-51: Annual Discharge of Sg. Padas at Beaufort JPS (1980-2006)

10 100 1000 10000 Return Period (year)

Figure C-52: Frequency Analysis of Annual Floods in Sg. Pad as at Beaufort JPS (I 980- 2006)

141 SUNGAI KINABATANGAN AT BALAT Location

Description by DID, SABAH Summary of Data

Not Available Sungai Kinabatangan at Name Balat 2 Area (km ): 10800 Elevation (m): . - Average Rainfall (mm) Water Use Total Mean yearly (m 3/s): 406.17 Mean of "Min"s yearly (m 3/s) 48.37 Mean of"Max"s yearly (m 3/s): 1681.52 Absolute Min, yearly (m 3/s): 7.49 Absolute Max yearly (m 3/s): 3611.6 Softcopy Streamflow Data Source: 1969-2006, DID, Sabah, Malaysia

142 -+-Annual Mean -10--Annual Flood Annual Drought

4000

3500 ------~ ------3000 .!!? :§. 2500 E'Q) 2000 .r:"' 1500 "Ill i5 1000 500 ~----

0 -1--~~,-----,---,-,-. -~-~-.-.-,-,-,-.-,-,-,-,-,-,-.-,--,--,-,-,-,-,---.------r-- mmwwmmmmwmmmmwwwwwwwwwwwooooooooo~~~~~~~~~~~~~~~~~~~~~~~~NNNNNNNNN ~~~~~oooooooooooooooooowwwwwwwwwwooooooooo m~oowo~N~~~m~oowo~Nw~~m~oowo~Nw~~m~oo Year

Figure C-53: Annual Discharge ofSg. Kinabatangan at Balat (1978-2006)

-+-Plotting Position (Weibull) -+-Pearson Ill Log-Normal 3 I · ·· Log-Pearson HI """'*'-Gumbel Type I _._Log-Normal 2 I

10 100 1000 10000 Return Period (Year)

Figure C-54: Frequency Analysis of Annual Floods in Sg. Kinabatangan at Balat (1978- 2006)

143 SUNGAI BAJA YO AT BEDUKAN Location

Description by DID, SABAH Summary of Data

Not Available Name Sungai Baiavo at Bedukan 2 Area (km ): 176 Elevation (m): - Average Rainfall (mm) Water Use Total Mean yearly (m 3/s): 5.95 Mean of 11 Min 11 s yearly (m 3/s) 1.48 Mean of"Max"s yearly (m 3/s): 55.15 Absolute 1\l!in, yearly (m 3/s): 0.08 Absolute Max yearly (m 3/s): 92.39 Softcopy Streamflow Data Source: 1969-2006, DID, Sabah, Malaysia

144 1-+-Annual Mean ---~>-Annual Flood Annual Drought I

100 90 80 ~ 70 .§.., 60 ~ 50 - 1! 40 i5""' 30 20 --- - 10

0 ------,---,------,--- ~ ~ ~ ~ ~ N N N N 0 0 0 0 ~ 0 0 0 0 0 "' "' "' "' "' "' "' ~ "'N "'w ..."' "' "'Ol "' "' "' 0 N w Ol "' "" "' "'Year

Figure C-55: Annual Discharge ofSg Baiayo at Bedukan (1993-2006)

-+-Plotting Position (Weibull) _... Pearson Ill log-Normal 3 I log-Pearson Ill -.-Gumbel Type I -----log-Normal2 I I .. ,. - 1-- , ---1---

i I li

10 100 1000 10000 Return Period (Year) ~-~~~--~~~~~-~~~~~~~~~~~~~----Figure C-56: Frequency Analysis of Annual Floods in Sg Baiayo at Bedukan (1993- 2006)

145 SUNGAI APIN-APIN AT WATERWORKS Location

Description by DID, SABAH Summary of Data

Not Available Sungai A pin-A pin at Name Waterworks 2 Area (km ): 133 Elevation (m): - Average Rainfall (mm) Water Use Total Mean yeariy (m3/s): 4.14 Mean of"Min"s yearly (m 3/s) 0.8 Mean of"Max"s yearly (m 3/s): 89.98 Absolute Min, yearly (m 3/s): 0.22 Absolute Max yearly (m 3/s): 160.62 Softcopy Streamflow Data Source: 1969-2006, DID, Sabah, Malaysia

146 j-+-Annual Mean -11-Annual Flood Annual Drought j

180 160 140 ~ 120 E. " 100 E' .l:"' 80 ~ 60 ------i5 40 20 ------

0 ·~~~"~...... ' '~

0 0 0 0 0 0 0 "'0 "'0 "'0 "'0 "'0 "'0 "'0 0 ~ ~ 0> Year "" "' "'

Figure C-57 : Annual Discharge of Sg. Apin-Apin at Waterworks (I 996-2006)

-+-Plotting Position (Weibull) ...... Pearson Ill Log-Normal 3 I Log-Pearson Ill --+-Gumbel Type I -+-Log-Normal 2 I

10 100 1000 10000 Return Period (Year) Figure C-58: Frequency Analysis of Annual Floods in Sg. Apin-Apin at Waterworks (I 996-2006)

P7 SUN GAl LABAU AT SINUA Location

Description by DID, SABAH Summary of Data

Not Available Name I Sungai Labau at Sinua 2 Area (km ): - . Elevation (m): - Average Rainfall (mm) Water Use Total Mean yearly (m 3/s): 5.52 Mean of"Min"s yearly (m 3/s) 0.87 Mean of"Max"s yearly (m 3/s): 254.51 Absolute Min, yearly (m 3/s): 0.3 Absolute Max yearly (m 3/s): 538.28 Softcopy Streamflow Data Source: 1969-2006, DID, Sabah, Malaysia

148 -+--Annual Mean _._Annual Flood Annual Drought

600

500

{!; 400 E. E'"' 300 .c"' lil 200 i5

100 ------

0 ----.

~ ~ ~ ~ ~ ~ 0 0 0 0 0 0 0 0 "'0 "'0 "'0 "'0 "'0 "'0 "'0 "'0 "' "' "'_,. "' "' "' "' ~ _,. "' "'w "' "' "'Ol "' "'00 "' 0 w Ol "' "' "" "'Year "' "' ""

Figure C-59: Annual Discharge of Sg. Labau at Sinua (1993-2006)

10 100 1000 10000 Return Period (Year)

Figure C-60: Frequency Analysis of Annual Floods m Sg. Labau at Smua (1993-2006)

149 SUNG AI KEGIBANGAN AT TAMPIAS Location

Description by DID, SABAH Summary of Data

Not Available Sungai Kegibangan at Name Tampias 2 Area (km ): 800

Elevation (m): " Average Rainfall (mm) Water Use Total Mean yearly (m 3 is): 44.12 Mean of "Min"s yearly (m 3/s) 8.49 Mean of 11 Max"s yearly (m 3/s): 568.19 Absolute Min, yearly (m 3/s): 2.4 Absolute Max yearly (m 3/s): 709.92 Softcopy Streamflow Data Source: 1969-2006, DID, Sabah, Malaysia

150 -+-Annual Mean ---Annual Flood Annual Drought

800.00 700.00

~ 600.00 M .s 500.00 ----· -·····----=--~------... ------:g. 400.00 ~ '5" 300.00 i5"' 200.00 100.00 ------·----- 0. oo L--~-~--=-=~-==-::::::=:::~. =-=-=-~.-=-=-=-~.~::.=~- ==-=-~.=-=-=--~.-=-=--=:--,---, (0 0 0 0 t:l 0 (0 "'0 0"' "'0 0 0"' CX> 0 w (J') Year "' "'

Figure C-61: Annual Discharge of Sg. Kegibangan at Tampias (1997-2006)

-+-Plotting Position (Weibull) --a-- Pearson Ill Log-Normal 3 I Log-Pearson Ill --+-Gumbel Type I _.._log-Normal 2

10 100 1000 10000 Return Period (Year)

Figure C-62: Frequency Analysis of Annual Floods in Sg. Kegibangan at Tampias (1997- 2006)

l.J 1 SUNGAI LIWAGU AT MARINGKAN Location

Description by DID, SABAH Summary of Data

Not Available Sungai Liawagu at Name Maringkan 2 Area (km ): 2000 Elevation (m): Average Rainfall (mm) Water Use Total Mean yearly (m 3/s): 37.05 Mean of"Min"s yearly (m 3/s) 8.09 Mean of"Max 11 s yearly (m 3/s): 284.64 Absolute Min, yearly (m3/s): 2.4 Absolute Max yearly (m 3/s): 395.68 Softcopy Stream flow Data Source: 1969-2006, DID, Sabah, Malaysia

152 [--+-Annual Mean -a- Annual Flood Annual Drought I

450 400-

~ 350 .!!!. 'E 3oo '\ ------­ -; 250 Cl tv 200 ·-~----- .c ~ 150 Ci 100

50 ..... -----"=-...~~=--=-~=-=--=+=--=-+-·==+=-==+-

0+-- --~--,----, N N N N N 0 0 0 8 0 8 0 ~ w ~ ~ Year

Figure C-63: Annual Discharge of Sg. Liwagu at Maringkan (1997 -2006)

-+-Plotting Position (Weibull) ---ll- Pearson Ill Log-Normal 3 Log-Pearson Ill .....,_Gumbel Type I __..._Log-Normal 2

1000

"gM • 100 ~ ~ u .•c

10

10 100 1000 10000 Return Period (Year) Figure C-64: Frequency Analysis of Annual Floods in Sg. Liwagu at Maringkan (1997- 2006)

153 SUNGAI MOYOG AT PENAMPANG Location

Description by DID, SABAH Summary of Data

Not Available Sungai Moyog at Name Pen am pang 2 Area (km ): 191 Elevation (m): Average Rainfall (mm) Water Use Total Mean yearly (m 1 /s): 14.9 Mean of"Min"s yearly (m 1/s) 1.3 Mean of "Max"s yearly (m1/s): 295.76 Absolute Min, yearly (m1/s): 0.21 Absolute Max yearly (m1/s): 507.28 Softcopy Streamflow Data Source: 1969-2006, DID, Sabah, Malaysia

154 -+-Annual Mean ~-Annual Flood Annual Drought

600

500 ~ s"' 400 Q) I:' 300 .<: (J" rn 200 i5 100

0 • *-*-~ ~ 11 * \ t _* ~A II n !J !J * * n.. n ,. • w· a t ,. ,...... _.. _ , ____.__,...... mmmmmmmmmwmwwmwwmwwmwwwwwwwwwwwmwooo~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~NNN ~mm~~~~~~~~~~~~~oooooooooooooowwwmwwwmwwooo ~oowo~Nw~~m~oowo~Nw~~m~oowo~Nw~~m~oowo~N Year

Figure C~65: Annual Discharge of Sg. Moyog at Penampang(l969~2006)

-+-Plotting Position (Weibull) ____._._Pearson Ill Log-Normal 3

Log-Pearson HI ~Gumbel Type 1 _._Log-Normal 2 10000

1000

10 100 1000 100.,1'1 Return Period (Year)

Figure C~66: Frequency Analysis of Annual Floods in Sg. Moyog at Penampang(l969- 2006)

155 SUNGAI LIWAGU AT KINA8ALU PARK Location

Description by DID, SABAH Summary of Data

Not Available Sungai Liwagu at Name Kinabalu Pari Area (km'): I I Elevation (m): - Average Rainfall (mm) Water Use Total Mean yearly (m 3/s): 0.57 Mean of"Min"s yearly (m 3/s) 0.12 Mean of"Max"s yearly (m 3/s): 22.32 Absolute Min, yearly (m 3/s): 0.06 Absolute Max yearly (m 3/s): 91.34 Softcopy Streamflow Data Source: I 969-2006, DID, Sabah, Malaysia

156 -+-Annual Mean -11-Annual Flood Annual Drought

100 90 80

~ 70 .§. 60 Cl> E' 50 "5"' 40 i5"' 30 - 1- -• \ - 20 10 ,.j L~..

~-----~-9_9_2----1-99-4----1-9-96_____ 19_9_8----~-~-a~----2-0-02 _____ 20_0_4 ____2_0_06----2-0_0_8~ Figure C-67: Annual Discharge of Sg. Liwagu at Kinabalu Park (1993-2006)

-+--Plotting Position (weibull) -11-- Pearson Ill Log-Nonnal 3 Log-Pearson Ill --li(-Gumbel Ty e 1 ...... Log-Normal 2 10000

1000

~.s •~ 100

~• 0 i5•

10

10 100 1000 10000 Retum Period (Year) Figure C-68: Frequency Analysis of Annual Floods in Sg. Liwagu at Kinabalu Park ( 1993-2006)

157 SUNGAI TUARAN AT P.H N0.1 Location

sj(·' j '·'·, I' j \ N"···- '"

Description by DID, SABAH Summary of Data

Not Available Name Sungai Tuaran at P.H No.I 2 Area (km ): 695 Elevation (m): - Average Rainfall (mm) Water

Use ' Total Mean yearly (m 3 /s): 34.05 Mean of"Min"s yearly (m 3/s) 3.75 Mean of"Max"s yearly (m 3/s): 427.6 Absolute Min, yearly (m3/s): 0.81 Absolute Max yearly (m 3/s): 902.89 Softcopy Streamflow Data Source: 1969-2006, DID, Sabah, Malaysia [-::__.._Annual Mean ,_,..__Annual Flood Annual DroughiJ

1000 900 ------800 700 600 500

~ (0 (0 (0 (0 (0 (0 (0 0 (0 (0 (0 0"' "'0 "' "' '£ Ol 0 "' "' Year "' "'

Figure C-69: Annual Discharge ofSg. Tuaran at P.H no. I (1982-2000)

-·• ··Pearson !II Log-Normal 3

100000

10000

10 100 1000 10000 Retum Period (Year)

Figure C-70: Frequency Analysis of Annual Floods in of Sg. Tuaran at P .H no I ( 1982- 2000)

159 SUNGAI BONGAN AT TIMBANG BATU Location

Description by DID, SABAH Summary of Data

Not Available Sungai Bongan at Name Tim bang Batu 2 Area (km ): 570 Elevation (m): - Average Rainfall (mm) Water Use Total Mean yearly (m 3 /s): 15.08 Mean of"Min"s yearly (m 3/s) 2.48 Mean of"Max"s yearly (m 3/s): 470.4 Absolute Min, yearly (m 3/s): 0.81 3 Absolute Max yearly (111 /s): 1996.2 Softcopy Streamflow Data Source: 1969-2006, DID, Sabah, Malaysia

160 !---+--Annual Mean -11-Annual Flood Annual Drought I

2500

2000 ~ .§..., 1500 ------E' ~ 1000 ~ i5 500

0 '.~

~ ~ ~ ~ ~ ~ ~

Figure C-71: Annual Discharge of Sg. Bongan at Tim bang Batu (1988-2006)

-+-Plotting Position (Weibull) --a-- Pearson Ill Log.Normal3

---)~:(,-Gumbel Type 1 ...... ,...Log-Normal2 100000

10000

1000

100.

10

10 100 1000 10000 Return Period (Year) Figure C-72: Frequency Analysis of Annual Floods in Sg Bongan at Tim bang Batu (1988-2006)

161 SUNGAI BENGKOKA AT KOBON Location

Description by DID, SABAH Summary of Data

Not Available Sungai Bengkoka at Name Kobon 2 Area (km ): 700 Elevation (m): Average Rainfall (mm) Water Use Total Mean yearly (m 3/s): 24.48 Mean of"Min"s yearly (m 3/s) 2.53 Mean of"Max"s yearly (m 3/s): 602.99 Absolute Min, yearly (m 3/s): 0.11 Absolute Max yearly (m 3/s): 1631.3 Softcopy Streamflow Data Source: 1969-2006, DID, Sabah, Malaysia

162 !-+-Annual Mean -II-· Annual Flood Annual Drought I

1800 1600 1400 ~ 1200 .s 1000 Cl "~ 800 .s:"' 600 i5"'" 400 200 0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~NNNNNNNN ~ww~w~wwwwwwwwwwmmwwmwwwwwwwwwwwwooooooooo mmm~~~~~~~~~~~~m~~oooooooooommmwwwmwwmooooooooo ~oowo~Nw~~m~oowo~Nw~~m~oowo~Nw~~m~oowo~Nw~~m~oo Year

Figure C-73: Annual Discharge ofSg. Bengkoka at Kobon (1969-2006)

log-Normal3

10000

t- 1000

100

10 100 1000 10000 Return Period (Year) Figure C-74: Frequency Analysis of Annual Floods in Sg. Bengkoka at Kobon (1969- 2006)

163 SARAWAK

164 MERINGGU AT SUNGAI KETUP

SADONG BASIN

'"""' MAl~ BASIN BOUNDAAY CAlCHfAEN! BOUNDARY ROMl e RAINfALL STATION ' RIVER GAUGE SlATIO'I SAMARAHAN BASIN

MAIN BASIN BOUNDARY BTG, SAOONG CATCHMEriT

Sg Ketup at Meringgu

110'JOE

Description by DID, SARA W AK Summary of Data

NOT AVAILABLE I Sungai Ketup At Name Meringgu 2 Area (km ): 338.2 Elevation (m): Average Rainfall (mm) Water Use I Total Mean yearly (m3/s): 19.94 Mean of"Min"s yearly (m 3/s) 3.57 Mean of 11 Max"s yearly (rn 3/s): 78.99 Absolute Min, yearly (m 3/s): 0.31 Absolute Max yearly (m 3/s): 119.61 Source I Softcopy Waterlevel Data, 1981-2005, DID, Sarawak

165 I-+- Annual Mean _,__Annual Flood Annual Drought I

140 -

120

c;;- 100 0> .§. 80

"'~ .s::.. 60 (.) i5"' 40

20 -

0 ,----,-----1 ~.-1

~ ~ ~ ~ ~ ~ ~ ~ ~- ~ ~ ~ ....\...... 1...... ~~ ~ ~ ~ ~ (0 (0 (0 (0 (0 (0 (0 (0 (0 (0 (0 co co <0 C> C> C> C> C> C> C> -J 00 00 00 00 00 00 00 CO CD CO CO (0 (0 (0 (0 (0 (0 "'C> "'C> "'C> "'"'"'C> C> C> "'C> "'C> (0 C> _,.. "'-JOO ~ "' "' _,.. "' Year

Figure C-75: Annual Discharge ofSungai Ketup at Meringgu (1981-2005)

--.-Plotting Position (weibull) -II- Pearson Ill Log-Normal 3 ! I Log·Pearson Ill --+--Gumbel Type I ---+-Log-Normal 2

10 100 1000 10000 Return Period (Year) Figure C-76: Frequency Analysis of Annual Floods ofSungai Ketup at Meringgu (1981- 2005)

166 BATANG AI AT LUBOK ANTU LUPARBASIN

SO<.ITH CHI~~ SE~ 111"00' Ei 112'00" E '

1'l0' ~

Batang Ai at Lubok Antu

10 1'00'"' ••

111'00 E

Description by DID, SABAH Summary of Data

Station No. 1018401 Name Batang Ai at Lubok Antu BATANG AI AT LUBOK ANTU 2 Area (km ): 1300 Elevation (m): 26 Gauging site:- Average Rainfall (mm) Longitude & Latitude:- I I 1"49'35" E 0 1'02'35" N. Water Use 2 Catchment Area:- 1300 km Total Mean yearly (m 3/s): 124.52 Elevation above mean sea level:- 26m Mean of "Min"s yearly (m 3/s) 27.78 Catchment characteristics:- Mean of "Max"s yearly (m 3/s): 425.86 3 (k) Shape:- The max1mum length and breadth of the Absolute Min, yearly (m /s): 1.39 3 catchment arc 62 km and 33 km respectively Absolute Max yearly (m /s): 682.77 (I) Topography:- Gently sloping to steep land Softcopy Waterlevel Data, (m) Vegetation :-Mainly Forest 1981-2005, DID, Sarawak (n) Soil Cover:- Skeletal Soils and Red Yellow Podzolic Source Streamflow and River Soil Suspended Records, 1975- (o) Rocl{ Type: - Sands, clays, sedimentary and 1990 metamorphic. Ranged or observations:- The range of river stages observed is from 20.46m to 25.6lm while discharge measurements have been taken between 20.92m and 23.77m above mean sea level.

167 !-+-Annual A~oerage _.__Annual Flood Annual Drought I

800 700

~ 600 ~ 'E soo ~ 400 ~ "5"' 300 i5"' 200 -- 100

0 +----~---~- 1975 1980 1985 1990 1995 2000 2005 2010 Year

Figure C-77: Annual Discharge ofBatang Ai at Lubok Antu, Sarawak (1977-2005)

-+-Plotting Position {wei bull) --• -Pearson Ill Log-Normal3 Log-Pearson Ill --*-Gumbel Type I -+- Log-Nonnal2 10000

---1 fr'~~~~-r~rrr~-=~t~ffrf@Itt~ 1000 I I ' - - - l I :t=t ! I -1 ' -:=i~$~§F _:A

~ .." • 100 •~ -

10 ·-

- I !

100 1000 10000 Rotum Period (Year) Figure C-78: Frequency Analysis of Annual Floods ofBatang Ai at Lubok Antu, Sarawak ( 1977 -2005)

168 SUNG AI SADONG AT SERIAN SADONG BASIN

~·· IMJN SASIN BOU~DM'tY CAl~HMONl SOU~1JAAI ROIIt :• ~ r; G RJ,;~FA:.l STATI~N ' RIVEQGAU:;tSTAliCN SAIAARAIWl BASIN

MAIN BASIN BOUNDARY

Sungai Sado11g at Serian

• INDONESIA

Description by DID, SABAH Summary of Data

Station No. 1018401 Name Sungai Sadong at Serian SUNGAI SA DONG AT SERIAN 2 Area (km ): 941 Elevation (m): Gauging site:- Average Rainfall (mm) Longitude & Latitude:- 110"34'00" E 01'09'35" N. Water Use 2 Catchment Area:- 941 km Total Mean yearly (m3/s): 56.81 Elevation above mean sea level:- Mean of"Min"s yearly (m 3/s) 5.25 Catchment ch;u·actcristics:- Mean of"Max"s yearly (m 3/s): 266.49 3 lrl Shape:- The max unum length and breadth of the Absolute Min, yearly (m /s): 0.33 3 catchment are 41 km and 49 km respectively Absolute Max yearly (m /s): 392.04 (q) Topography:- Moderately steep to undulating land Softcopy Waterlevel Data, (r) Vegetation :-Mainly Forested areas 1981-2005, DID, Sarawak (s) Soil Cover:- Gley soils with poorly drained sands and Source Streamflow and River clay Suspended Records, 1975- (t) Rocl' Type -Mainly sr;:dimentary rocks 1990 Hanged of observations:- The range of river stages observed is from 2.10 m to 9.76 m while discharge measurements have been taken between 2.66 m and 9.76·m abo:ve mean sea level

169 E!'nnual Mean _._Annual Flood Annual Drought I

800 700

- 600 "' ~ 500 ------+-

1l, 400 - - - ~ ~ \ '5"' 300 i5"' 200 Vw 100 /

0 +-.~~ -,-,-. ,-,-,-, --- -,------·,-,-,-,-,-,-,-.-.-,-,-.-,-.-.-,-, ,--;---r--r-,--,-,--,--,

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~NNNNNNNNN ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ffiffiffiffiffiffiffiffi888888888 wo~N~~~~~~o~N~~~~oo~o~N~~~~oowo~N~~m~oowo~N~~m~oo Year

Figure C-79: Annual Discharge of Sungai Sadong at Serian, Sarawak (1968-2005)

10000

•~ 100

"~ i5

10 100 1000 10000 Return Period (Year)

Figure C-80: Frequency Analysis of Annual Floods of Sungai Sadong at Serian, Sarawak (1968-2005)

170 TUBA AT SUNGAI SEBUYAU LUPARBASIN

'111"00' ~ ... I.WNSA!lrNBOUNIJAA'o' CA1CHI.IE~l a(JjJ!jDAlf< . ~~ llJ\JNFiol.lSTATION ' R!VI.fl G~IJGE SIA!IOO SARI8AS !!ASIN

OllOONGBP.SIN

G 5 10 •• '' Description by DID, SABAH Summary of Data

NOT AVAILABLE Name Sungai Tuba at Sebuyau 2 Area (km ): 28.5 Elevation (m): Average Rainfall (mm) Water Use Total Mean yearly (m 3/s): 2.69 Mean of 11 Min 11 s yearly (m 3/s) 0.75 Mean of"Max"s yearly (m 3/s): 7.88 Absolute Min, yearly (m 3/s): 2.64 Absolute Max yearly (m3/s): 10.39 Softcopy Waterlevel Data, Source 1987-2000, DID, Sarawak

171 --+-Annual Mean ------Annual Flood Annual Drought

12 -

10 -

:w 8 "'.§.. 6 "'"'~ .;:;."' " 4 i5"' 2

0 ~ --,- ~ ~ ~ ~ ~ ~ ~ ~ N N <0 <0 <0 <0 <0 <0 <0 <0 <0 <0 <0 <0 <0 <0 0 0 co co co co <0 <0 <0 <0 <0 <0 <0 <0 <0 <0 0 0 Ol co <0 0 ~ N w .. Ol co <0 0 ~ " Year "' ""

Figure C-81: Annual Discharge ofSungai Tuba at Sebuyau, Sarawak (1987-2000)

-+-Plotting Position (Weibull) • -Pearson Ill Log-Normal 3 I Log-Pearson Ill ~Gumbel Type 1 ...... Log-Normal 2

.

: I

10 100 1000 10000 Return Period (Year) Figure C-82: Frequency Analysis of Annual Floods of Sunga1 Tuba at Sebuyau, Sarawak (1 987-2000)

172 SUNGAI SARAWAK KIRI AT GIT

Sarawak Basin

110'00'E

Sg Sarawak Kanan at Buan Bidi, Kuching

Description by DID, SABAH Summary of Data

NOT AVAILABLE Sungai Sarawak Kanan at Name Buan Bidi Area (km'): 425 Elevation (m): Average Rain fall ( m m) Water Use Total Mean yearly (m 3 /s): 33.01 Mean of "Min"s yearly (m 3/s) 8. I 8 Mean of"Max"s yearly (m 3/s): 468.81 Absolute Min, yearly (m 3/s): 0.6 Absolute Max yearly (m 3/s): 866.33 Softcopy Waterlevel Data, Source 1987-2000, DID, Sarawak

173 E Annual Average _,.__Annual Flood Annual Drought I

1000 900 en 800 ;;; 700 ·--·f­ e 600 w ~ 500 . <( ·v······ J: 400 - -- -- ..... 1\ ·-~- ·--7" () rn 300 ~ '"',/ ~ - 0 200 100 ..___.. . - --·----·· 0 .-----,

~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Figure C-83: Annual Discharge of Sungai Sarawak at Kg. Git, Sarawak (\ 977-\ 990)

-+--Plotting Posit1on (weibull) Log-Normal3

10000 ---__;-

1000

I ~ i :!;

l I- -~--

10. _-_I-

-! ! --- :--- "!

I r -~

10 100 1000 10000 Return Period (Year) Figure C-84: Frequency Analysis of Annual Floods of Sungai Sarawak at Kg. Git, Sarawak ( \ 987-2000)

174